Displaying publications 541 - 560 of 837 in total

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  1. Dye degradation, antibacterial and in-silico analysis of Mg/cellulose-doped ZnO nanoparticles
    Ikram M, Mahmood A, Haider A, Naz S, Ul-Hamid A, Nabgan W, et al.
    Int J Biol Macromol, 2021 Aug 31;185:153-164.
    PMID: 34157328 DOI: 10.1016/j.ijbiomac.2021.06.101
    Various concentrations of Mg into fixed amount of cellulose nanocrystals (CNC)-doped ZnO were synthesized using facile chemical precipitation. The aim of present study is to remove dye degradation of methylene blue (MB) and bactericidal behavior with synthesized product. Phase constitution, functional group analysis, optical behavior, elemental composition, morphology and microstructure were examined using XRD, FTIR, UV-Vis spectrophotometer, EDS and HR-TEM. Highly efficient photocatalytic performance was observed in basic medium (98%) relative to neutral (65%), and acidic (83%) was observed upon Mg and CNC co-doping. Significant bactericidal activity of doped ZnO nanoparticles depicted inhibition zones for G -ve and +ve bacteria ranging (2.20 - 4.25 mm) and (5.80-7.25 mm) for E. coli and (1.05 - 2.75 mm) and (2.80 - 4.75 mm) for S. aureus at low and high doses, respectively. Overall, doped nanostructures showed significant (P 
    Matched MeSH terms: Escherichia coli/drug effects
  2. Fulltext Recovery of recombinant Mycobacterium tuberculosis antigens fused with cell wall-anchoring motif (LysM) from inclusion bodies using non-denaturing reagent (N-laurylsarcosine)
    Mustafa AD, Kalyanasundram J, Sabidi S, Song AA, Abdullah M, Abdul Rahim R, et al.
    BMC Biotechnol, 2019 05 14;19(1):27.
    PMID: 31088425 DOI: 10.1186/s12896-019-0522-x
    BACKGROUND: The current limitations of conventional BCG vaccines highlights the importance in developing novel and effective vaccines against tuberculosis (TB). The utilization of probiotics such as Lactobacillus plantarum for the delivery of TB antigens through in-trans surface display provides an effective and safe vaccine approach against TB. Such non-recombinant probiotic surface display strategy involves the fusion of candidate proteins with cell wall binding domain such as LysM, which enables the fusion protein to anchor the L. plantarum cell wall externally, without the need for vector genetic modification. This approach requires sufficient production of these recombinant fusion proteins in cell factory such as Escherichia coli which has been shown to be effective in heterologous protein production for decades. However, overexpression in E. coli expression system resulted in limited amount of soluble heterologous TB-LysM fusion protein, since most of it are accumulated as insoluble aggregates in inclusion bodies (IBs). Conventional methods of denaturation and renaturation for solubilizing IBs are costly, time-consuming and tedious. Thus, in this study, an alternative method for TB antigen-LysM protein solubilization from IBs based on the use of non-denaturating reagent N-lauroylsarcosine (NLS) was investigated.

    RESULTS: Expression of TB antigen-LysM fusion genes was conducted in Escherichia coli, but this resulted in IBs deposition in contrast to the expression of TB antigens only. This suggested that LysM fusion significantly altered solubility of the TB antigens produced in E. coli. The non-denaturing NLS technique was used and optimized to successfully solubilize and purify ~ 55% of the recombinant cell wall-anchoring TB antigen from the IBs. Functionality of the recovered protein was analyzed via immunofluorescence microscopy and whole cell ELISA which showed successful and stable cell wall binding to L. plantarum (up to 5 days).

    CONCLUSION: The presented NLS purification strategy enables an efficient and rapid method for obtaining higher yields of soluble cell wall-anchoring Mycobacterium tuberculosis antigens-LysM fusion proteins from IBs in E. coli.

    Matched MeSH terms: Escherichia coli/metabolism
  3. Antibacterial efficacy of poly(hexamethylene biguanide) immobilized on chitosan/dye-modified nanofiber membranes
    Xu FX, Ooi CW, Liu BL, Song CP, Chiu CY, Wang CY, et al.
    Int J Biol Macromol, 2021 Jun 30;181:508-520.
    PMID: 33775766 DOI: 10.1016/j.ijbiomac.2021.03.151
    This study aimed to develop a novel electrospun polyacrylonitrile (PAN) nanofiber membrane with the enhanced antibacterial property. The PAN nanofiber membrane was first subjected to alkaline hydrolysis treatment, and the treated membrane was subsequently grafted with chitosan (CS) to obtain a CS-modified nanofiber membrane (P-COOH-CS). The modified membrane was then coupled with different dye molecules to form P-COOH-CS-Dye membranes. Lastly, poly(hexamethylene biguanide) hydrochloride (PHMB) was immobilized on the modified membrane to produce P-COOH-CS-Dye-PHMB. Physical characterization studies were conducted on all the synthesized nanofiber membranes. The antibacterial efficacies of nanofiber membranes prepared under different synthesis conditions were evaluated systematically. Under the optimum synthesis conditions, P-COOH-CS-Dye-PHMB was highly effective in disinfecting a high concentration of Escherichia coli, with an antibacterial efficacy of approximately 100%. Additionally, the P-COOH-CS-Dye-PHMB exhibited an outstanding wash durability as its antibacterial efficacy was only reduced in the range of 5%-7% even after 5 repeated cycles of treatment. Overall, the experimental results of this study suggested that the P-COOH-CS-Dye-PHMB is a promising antibacterial nanofiber membrane that can be adopted in the food, pharmaceutical, and textile industries.
    Matched MeSH terms: Escherichia coli/drug effects
  4. Fulltext Clonal relatedness in the acquisition of intestinal carriage and transmission of multidrug resistant (MDR) Klebsiella pneumoniae and Escherichia coli and its risk factors among preterm infants admitted to the neonatal intensive care unit (NICU)
    Lee YQ, Ahmad Kamar A, Velayuthan RD, Chong CW, Teh CSJ
    Pediatr Neonatol, 2021 03;62(2):129-137.
    PMID: 33218933 DOI: 10.1016/j.pedneo.2020.10.002
    BACKGROUND: Gastrointestinal carriage of multidrug resistant (MDR) Gram-negative bacilli, especially Klebsiella pneumoniae and Escherichia coli, was highly associated with severe nosocomial infections. The main objectives of this study were to determine the clonal relatedness of intestinal carriage and transmission risk factors of MDR E. coli and K. pneumoniae amongst preterm infants admitted to the neonatal intensive care unit (NICU).

    METHODS: A prospective cohort study of preterm infants with gestational age 

    Matched MeSH terms: Escherichia coli/isolation & purification*
  5. Preparation and photodynamic bactericidal effects of curcumin-β-cyclodextrin complex
    Lai D, Zhou A, Tan BK, Tang Y, Sarah Hamzah S, Zhang Z, et al.
    Food Chem, 2021 Nov 01;361:130117.
    PMID: 34058659 DOI: 10.1016/j.foodchem.2021.130117
    To overcome the poor water solubility of curcumin, a curcumin-β-cyclodextrin (Cur-β-CD) complex was prepared as a novel photosensitizer. Fourier-transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) were used to verify the formation of Cur-β-CD. Furthermore, the ROS generation capacity and photodynamic bactericidal effect were measured to confirm this Cur-β-CD complex kept photodynamic activity of curcumin. The result showed Cur-β-CD could effectively generate ROS upon blue-light irradiation. The plate count assay demonstrated Cur-β-CD complex possess desirable photodynamic antibacterial effect against food-borne pathogens including Staphylococcus aureus, Listeria monocytogenes and Escherichia coli. The cell morphology determined by scanning electron microscope (SEM) and transmission electron microscope (TEM) showed Cur-β-CD could cause cell deformation, surface collapse and cell structure damage of the bacteria, resulting in the leakage of cytoplasmic; while agarose gel electrophoresis and SDS-PAGE further illustrated the inactivation mechanisms by Cur-β-CD involve bacterial DNA damage and protein degradation.
    Matched MeSH terms: Escherichia coli/drug effects
  6. Heterologous Expression of PA8FAD9 and Functional Characterization of a Δ9-Fatty Acid Desaturase from a Cold-Tolerant Pseudomonas sp. A8
    Garba L, Ali MS, Oslan SN, Rahman RN
    Mol Biotechnol, 2016 Nov;58(11):718-728.
    PMID: 27629791
    Fatty acid desaturase enzymes are capable of inserting double bonds between carbon atoms of saturated fatty acyl-chains to produce unsaturated fatty acids. A gene coding for a putative Δ9-fatty acid desaturase-like protein was isolated from a cold-tolerant Pseudomonas sp. A8, cloned and heterologously expressed in Escherichia coli. The gene named as PA8FAD9 has an open reading frame of 1185 bp and codes for 394 amino acids with a predicted molecular weight of 45 kDa. The enzyme showed high Δ9-fatty acid desaturase-like protein activity and increased overall levels of cellular unsaturated fatty acids in the recombinant E. coli cells upon expression at different temperatures. The results showed that the ratio of palmitoleic to palmitic acid in the recombinant E. coli cells increased by more than twice the amount observed in the control cells at 20 °C using 0.4 mM IPTG. GCMS analysis confirmed the ability of this enzyme to convert exogenous stearic acid to oleic acid incorporated into the recombinant E. coli membrane phospholipids. It may be concluded that the PA8FAD9 gene from Pseudomonas sp. A8 codes for a putative Δ9-fatty acid desaturase protein actively expressed in E. coli under the influence of temperature and an inducer.
    Matched MeSH terms: Escherichia coli/genetics
  7. Fabrication of biodegradable Zn-Al-Mg alloy: Mechanical properties, corrosion behavior, cytotoxicity and antibacterial activities
    Bakhsheshi-Rad HR, Hamzah E, Low HT, Kasiri-Asgarani M, Farahany S, Akbari E, et al.
    Mater Sci Eng C Mater Biol Appl, 2017 Apr 01;73:215-219.
    PMID: 28183601 DOI: 10.1016/j.msec.2016.11.138
    In this work, binary Zn-0.5Al and ternary Zn-0.5Al-xMg alloys with various Mg contents were investigated as biodegradable materials for implant applications. Compared with Zn-0.5Al (single phase), Zn-0.5Al-xMg alloys consisted of the α-Zn and Mg2(Zn, Al)11 with a fine lamellar structure. The results also revealed that ternary Zn-Al-Mg alloys presented higher micro-hardness value, tensile strength and corrosion resistance compared to the binary Zn-Al alloy. In addition, the tensile strength and corrosion resistance increased with increasing the Mg content in ternary alloys. The immersion tests also indicated that the corrosion rates in the following order Zn-0.5Al-0.5MgEscherichia coli presented some antibacterial activity, while the Zn-0.5Al-0.5Mg significantly prohibited the growth of Escherichia coli. Thus, Zn-0.5Al-0.5Mg alloy with appropriate mechanical properties, low corrosion rate, good biocompatibility and antibacterial activities was believed to be a good candidate as a biodegradable implant material.
    Matched MeSH terms: Escherichia coli/drug effects
  8. Studies of bacterial disease in West Malaysian Orang Asli. Distribution of enteropathogens
    Haug NL, Davis CE, Anandan J, Lim TW
    Med J Malaya, 1969 Sep;24(1):24-31.
    PMID: 4243839
    Matched MeSH terms: Escherichia coli/isolation & purification
  9. Rational design of bis-indolylmethane-oxadiazole hybrids as inhibitors of thymidine phosphorylase
    Taha M, Rashid U, Imran S, Ali M
    Bioorg Med Chem, 2018 07 23;26(12):3654-3663.
    PMID: 29853339 DOI: 10.1016/j.bmc.2018.05.046
    Inhibition of Thymidine phosphorylase (TP) is continuously studied for the design and development of new drugs for the treatment of neoplastic diseases. As a part of our effort to identify TP inhibitors, we performed a structure-based virtual screening (SBVS) of our compound collection. Based on the insights gained from structures of virtual screening hits, a scaffold was designed using 1,3,4-oxadiazole as the basic structural feature and SAR studies were carried out for the optimization of this scaffold. Twenty-five novel bis-indole linked 1,3,4-oxadiazoles (7-31) were designed, synthesized and tested in vitro against E. coli TP (EcTP). Compound 7 emerged as potent TP inhibitor with an IC50 value of 3.50 ± 0.01 μM. Docking studies were carried out using GOLD software on thymidine phosphorylase from human (hTP) and E. coli (EcTP). Various hydrogen bonding, hydrophobic interactions, and π-π stacking were observed between designed molecules and the active site amino acid residues of the studied enzymes.
    Matched MeSH terms: Escherichia coli/enzymology
  10. Characterization of quorum sensing genes and N-acyl homoserine lactones in Citrobacter amalonaticus strain YG6
    Kher HL, Krishnan T, Letchumanan V, Hong KW, How KY, Lee LH, et al.
    Gene, 2019 Feb 05;684:58-69.
    PMID: 30321658 DOI: 10.1016/j.gene.2018.10.031
    In the phylum of Proteobacteria, quorum sensing (QS) system is widely driven by synthesis and response of N-acyl homoserine lactone (AHL) signalling molecules. AHL is synthesized by LuxI homologue and sensed by LuxR homologue. Once the AHL concentration achieves a threshold level, it triggers the regulation of target genes. In this study, QS activity of Citrobacter amalonaticus strain YG6 which was isolated from clams was investigated. In order to characterise luxI/R homologues, the genome of C. amalonaticus strain YG6 (4.95 Mbp in size) was sequenced using Illumina MiSeq sequencer. Through in silico analysis, a pair of canonical luxI/R homologues and an orphan luxR homologue were identified and designated as camI, camR, and camR2, respectively. A putative lux box was identified at the upstream of camI. The camI gene was cloned and overexpressed in E. coli BL21 (DE3)pLysS. High-resolution triple quadrupole liquid chromatography mass spectrometry (LC-MS/MS) analysis verified that the CamI is a functional AHL synthase which produced multiple AHL species, namely N‑butyryl‑l‑homoserine lactone (C4-HSL), N‑hexanoyl‑l‑homoserine lactone (C6-HSL), N‑octanoyl‑l‑homoserine lactone (C8-HSL), N‑tetradecanoyl‑l‑homoserine lactone (C14-HSL) and N‑hexadecanoyl‑l‑homoserine lactone (C16-HSL) in C. amalonaticus strain YG6 and camI gene in recombinant E. coli BL21(DE3)pLysS. To our best knowledge, this is the first functional study report of camI as well as the first report describing the production of C14-HSL by C. amalonaticus.
    Matched MeSH terms: Escherichia coli/genetics
  11. Chitosan, gelatin and methylcellulose films incorporated with tannic acid for food packaging
    Halim ALA, Kamari A, Phillip E
    Int J Biol Macromol, 2018 Dec;120(Pt A):1119-1126.
    PMID: 30176328 DOI: 10.1016/j.ijbiomac.2018.08.169
    In this work, chitosan, gelatin and methylcellulose films incorporated with tannic acid (TA) were synthesised, characterised and applied for the first time to preserve cherry tomatoes (Solanum lycopersicum var. cerasiforme) and grapes (Vitis vinifera). The addition of TA at 15% (w/w) increased the transparency value of biopolymer films. The highest increment of transparency value was obtained for MC-TA film, increased from 0.572 to 4.73 A/mm. Based on antimicrobial study, the addition of TA improved the antibacterial properties of biopolymers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The ability of films to preserve both fruits was evaluated in a 14-day preservation study. The application of biopolymer films treated with TA has decreased the weight loss and browning index of fruits, as compared to control films. A significant reduction in the weight loss of cherry tomatoes wrapped with chitosan (from 21.3 to 19.6%), gelatin (from 22.1 to 15.5%) and methylcellulose (26.2 to 20.5%) films were obtained following TA treatment. Overall, results obtained from this study highlight the effects of TA on physiochemical properties of biopolymer films and their ability to preserve fruits.
    Matched MeSH terms: Escherichia coli/drug effects
  12. Synthesis, Bacterial biofilm inhibition and cytotoxicity of new N-Alkyl/aralkyl-N-(2,3-dihydro-1,4-benzodioxin-6-yl)-4-nitrobenzenesulfonamides
    Abbasi MA, Zeb A, Rehman A, Siddiqui SZ, Shah SAA, Shahid M, et al.
    Pak J Pharm Sci, 2020 Jan;33(1):41-47.
    PMID: 32122829
    The current research was commenced by reaction of 1,4-benzodioxane-6-amine (1) with 4-nitrobenzenesulfonyl chloride (2) in the presence of aqueous base under dynamic pH control at 9 to yield N-(2,3-dihydro-1,4-benzodioxin-6-yl)-4-nitrobenzenesulfonamide (3) which was further reacted with a series of alkyl/aralkyl halides (4a-i) in polar aprotic solvent using catalytic amount of lithium hydride which acts as base to afford some new N-alkyl/aralkyl-N-(2,3-dihydro-1,4-benzodioxin-6-yl)-4-nitrobenzenesulfonamides (5a-i). The projected structures of all the synthesized derivatives were characterized by contemporary techniques i.e., IR, 1H-NMR and EIMS. The biofilm Inhibitory action of all synthesized molecules was carried out against Escherichia coli and Bacillus subtilis. It was inferred from their results that 5f and 5e exhibited suitable inhibitory action against the biofilms of these bacterial strains. Moreover, their cytotoxicity was also checked and it was concluded that these synthesized molecules displayed docile cytotoxicity.
    Matched MeSH terms: Escherichia coli/drug effects
  13. Survival of antibiotic resistant Escherichia coli in vacuumpacked keropok lekor: Food safety alert among SME keropok lekor producers
    Wan-Hamat H, Lani MN, Hamzah Y, Alias R, Hassan Z, Mahat NA
    Trop Biomed, 2020 Mar 01;37(1):103-115.
    PMID: 33612722
    The microbiological quality of thirty ready-to-eat (RTE) keropok lekor (a sausage shape Malaysian fish product) was evaluated in comparison to microbiological guidelines for ready to eat foods. The two E. coli isolates were subjected to DNA sequencing, identified and tested for their resistance towards fifteen different antibiotics. The survival and growth of the isolated E. coli strains inoculated in keropok lekor at atmospheric air and vacuum packaging were also evaluated. Results revealed that four samples (13.33%) contained Enterobacteriaceae counts that exceeded the recommended allowable counts of 4.0 log10 CFU/g. Unsatisfactory level of coliforms (< 1.7 log10 CFU/g) was also observed in ten of the samples; two of which contained E. coli (2.1 ± 0.17 and 3.7 ± 0.02 log10 CFU/g), suggesting of poor hygiene and sanitation practices. While the 'Possible E10' E. coli strain was observably resistant towards Nalidixic acid (30µg) alone, B10 E. coli isolate was worryingly resistant towards Ampicillin (10µg), Ceftazidime (30µg), Ciprofloxacin (5µg), Ceftriaxone (30µg), Nalidixic acid (30µg) and Tetracycline (30µg). This study also revealed that the growth and survival of the 'Possible E10' and B10 E. coli strains were not significantly affected by vacuum packaging when stored at both 4°C and 28°C. Therefore, intervention programmes to alert and educate smallmedium enterprisers (SMEs) of keropok lekor producers on food safety as well as potential health risks that can be associated due to inappropriate handling procedures of such product, merits consideration.
    Matched MeSH terms: Escherichia coli/drug effects*
  14. Fulltext Enhancing recovery of bioactive compounds from Cosmos caudatus leaves via ultrasonic extraction
    Latiff NA, Ong PY, Abd Rashid SNA, Abdullah LC, Mohd Amin NA, Fauzi NAM
    Sci Rep, 2021 08 27;11(1):17297.
    PMID: 34453075 DOI: 10.1038/s41598-021-96623-x
    Cosmos caudatus (C. caudatus) is a medicinal plant that is high in bioactive compounds such as phenolics. In this study, an ultrasound extraction method was used to optimise the extraction of bioactive compounds from C. caudatus leaves. Response surface methodology (RSM) based on a Box-Behnken design (BBD) was applied to obtain the optimum extraction parameters which is solid-liquid ratio (10-30 g/mL), particle size (180-850 µm) and extraction time (20-30 min) for maximal quercitrin and total phenolic content (TPC) yields. Analysis of antimicrobial activity was performed against two human pathogenic microbes: Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) by the agar well diffusion method. The optimal ultrasonic extraction condition was as follow: solvent-liquid ratio of 1:28 (g/mL), particle size of 485 µm, and duration of 30 min, respectively. Remarkably, extraction using ultrasonic method had recovered more bioactive content and antioxidant activity than the Soxhlet method. The extract also exhibited good antimicrobial activities. Due to the above findings, the ultrasonic extraction was found to be suitable to improve recovery extraction of quercitrin and TPC from C. caudatus leaves. It also opens the possibility that the plant extract can be used for functional food and antimicrobial agents in various applications.
    Matched MeSH terms: Escherichia coli/drug effects
  15. Fulltext Bacterial Cellulose: Production, Characterization, and Application as Antimicrobial Agent
    Lahiri D, Nag M, Dutta B, Dey A, Sarkar T, Pati S, et al.
    Int J Mol Sci, 2021 Nov 30;22(23).
    PMID: 34884787 DOI: 10.3390/ijms222312984
    Bacterial cellulose (BC) is recognized as a multifaceted, versatile biomaterial with abundant applications. Groups of microorganisms such as bacteria are accountable for BC synthesis through static or agitated fermentation processes in the presence of competent media. In comparison to static cultivation, agitated cultivation provides the maximum yield of the BC. A pure cellulose BC can positively interact with hydrophilic or hydrophobic biopolymers while being used in the biomedical domain. From the last two decades, the reinforcement of biopolymer-based biocomposites and its applicability with BC have increased in the research field. The harmony of hydrophobic biopolymers can be reduced due to the high moisture content of BC in comparison to hydrophilic biopolymers. Mechanical properties are the important parameters not only in producing green composite but also in dealing with tissue engineering, medical implants, and biofilm. The wide requisition of BC in medical as well as industrial fields has warranted the scaling up of the production of BC with added economy. This review provides a detailed overview of the production and properties of BC and several parameters affecting the production of BC and its biocomposites, elucidating their antimicrobial and antibiofilm efficacy with an insight to highlight their therapeutic potential.
    Matched MeSH terms: Escherichia coli/drug effects
  16. Influence of pathogenic bacterial activity on growth of Scenedesmus sp. and removal of nutrients from public market wastewater
    Al-Gheethi AA, Mohamed RM, Jais NM, Efaq AN, Abd Halid A, Wurochekke AA, et al.
    J Water Health, 2017 Oct;15(5):741-756.
    PMID: 29040077 DOI: 10.2166/wh.2017.080
    The present study aims to investigate the influence of Staphylococcus aureus, Escherichia coli and Enterococcus faecalis in public market wastewater on the removal of nutrients in terms of ammonium (NH4-) and orthophosphate (PO43) using Scenedesmus sp. The removal rates of NH4- and orthophosphate PO43- and batch kinetic coefficient of Scenedesmus sp. were investigated. The phycoremediation process was carried out at ambient temperature for 6 days. The results revealed that the pathogenic bacteria exhibited survival potential in the presence of microalgae but they were reduced by 3-4 log at the end of the treatment process. The specific removal rates of NH4- and PO43- have a strong relationship with initial concentration in the public market wastewater (R2 = 0.86 and 0.80, respectively). The kinetic coefficient of NH4- removal by Scenedesmus sp. was determined as k = 4.28 mg NH4- 1 log10 cell mL-1 d-1 and km = 52.01 mg L-1 (R2 = 0.94) while the coefficient of PO43- removal was noted as k = 1.09 mg NH4- 1 log10 cell mL-1 d-1 and km = 85.56 mg L-1 (R2 = 0.92). It can be concluded that Scenedesmus sp. has high competition from indigenous bacteria in the public market wastewater to remove nutrients, with a higher coefficient of removal of NH4- than PO43.
    Matched MeSH terms: Escherichia coli/physiology
  17. Fulltext AidP, a novel N-Acyl homoserine lactonase gene from Antarctic Planococcus sp
    See-Too WS, Ee R, Lim YL, Convey P, Pearce DA, Yin WF, et al.
    Sci Rep, 2017 02 22;7:42968.
    PMID: 28225085 DOI: 10.1038/srep42968
    Planococcus is a Gram-positive halotolerant bacterial genus in the phylum Firmicutes, commonly found in various habitats in Antarctica. Quorum quenching (QQ) is the disruption of bacterial cell-to-cell communication (known as quorum sensing), which has previously been described in mesophilic bacteria. This study demonstrated the QQ activity of a psychrotolerant strain, Planococcus versutus strain L10.15T, isolated from a soil sample obtained near an elephant seal wallow in Antarctica. Whole genome analysis of this bacterial strain revealed the presence of an N-acyl homoserine lactonase, an enzyme that hydrolyzes the ester bond of the homoserine lactone of N-acyl homoserine lactone (AHLs). Heterologous gene expression in E. coli confirmed its functions for hydrolysis of AHLs, and the gene was designated as aidP (autoinducer degrading gene from Planococcus sp.). The low temperature activity of this enzyme suggested that it is a novel and uncharacterized class of AHL lactonase. This study is the first report on QQ activity of bacteria isolated from the polar regions.
    Matched MeSH terms: Escherichia coli/metabolism
  18. Site-Directed Mutagenesis of Cytochrome P450 2D6 and 2C19 Enzymes: Expression and Spectral Characterization of Naturally Occurring Allelic Variants
    Dong AN, Pan Y, Palanisamy UD, Yiap BC, Ahemad N, Ong CE
    Appl Biochem Biotechnol, 2018 Sep;186(1):132-144.
    PMID: 29524040 DOI: 10.1007/s12010-018-2728-0
    Genetic polymorphism of the cytochrome P450 (CYP) genes particularly affects CYP2D6 and CYP2C19 to a functionally relevant extent, and it is therefore crucial to elucidate the enzyme kinetic and molecular basis for altered catalytic activity of these allelic variants. This study explored the expression and function of the reported alleles CYP2D6*2, CYP2D6*10, CYP2D6*17, CYP2C19*23, CYP2C19*24, and CYP2C19*25 with respect to gene polymorphisms. Site-directed mutagenesis (SDM) was carried out to generate these six alleles. After DNA sequencing, the CYP2D6 and CYP2C19 wild types alongside with their alleles were each independently co-expressed with NADPH-CYP oxidoreductase (OxR) in Escherichia coli. The expressed proteins were analyzed using Western blotting, reduced carbon monoxide (CO) difference spectral scanning, and cytochrome c reductase assay. Results from Western blot revealed the presence of all CYP wild-type and allelic proteins in E. coli membrane fractions. The reduced CO difference spectra scanning presented the distinct peak of absorbance at 450 nm, and the cytochrome c reductase assay has confirmed that spectrally active OxR was expressed in each protein preparation. As a conclusion, the results obtained from this study have proven the CYP variants to be immunoreactive and spectrally active and are suitable for use to examine biotransformation and interaction mechanism of the enzymes.
    Matched MeSH terms: Escherichia coli/genetics
  19. Fulltext Screening for bacteriuria in Malaysian school children
    Zainal D, Baba A
    Singapore Med J, 1994 Aug;35(4):374-5.
    PMID: 7899895
    Urinary tract infection is the most common of bacterial infections. Screening children for asymptomatic bacteriuria to prevent pyelonephritis and renal scarring is widely recommended. In Malaysia no such attempt has been made to establish the prevalence of asymptomatic bacteriuria. Bacteriuria was screened among 44,816 healthy school children from three different districts in Kelantan. There were 23,132 boys and 21,684 girls. The prevalence of bacteriuria was 0.12% after second screening. Higher prevalence was seen in other reports.
    Matched MeSH terms: Escherichia coli/isolation & purification
  20. Electro-transformation of mefenamic acid drug: a case study of kinetics, transformation products, and toxicity
    Mussa ZH, Al-Qaim FF, Yuzir A, Latip J
    Environ Sci Pollut Res Int, 2019 Apr;26(10):10044-10056.
    PMID: 30756352 DOI: 10.1007/s11356-019-04301-3
    Poor removal of many pharmaceuticals and personal care products in sewage treatment plants leads to their discharge into the receiving waters, where they may cause negative effects for aquatic environment and organisms. In this study, electrochemical removal process has been used as alternative method for removal of mefenamic acid (MEF). For our knowledge, removal of MEF using electrochemical process has not been reported yet. Effects of initial concentration of mefenamic acid, sodium chloride (NaCl), and applied voltage were evaluated for improvement of the efficiency of electrochemical treatment process and to understand how much electric energy was consumed in this process. Removal percentage (R%) was ranged between 44 and 97%, depending on the operating parameters except for 0.1 g NaCl which was 9.1%. Consumption energy was 0.224 Wh/mg after 50 min at 2 mg/L of mefenamic acid, 0.5 g NaCl, and 5 V. High consumption energy (0.433 Wh/mg) was observed using high applied voltage of 7 V. Investigation and elucidation of the transformation products were provided by Bruker software dataAnalysis using liquid chromatography-time of flight mass spectrometry. Seven chlorinated and two non-chlorinated transformation products were investigated after 20 min of electrochemical treatment. However, all transformation products (TPs) were eliminated after 140 min. For the assessment of the toxicity, it was impacted by the formation of transformation products especially between 20 and 60 min then the inhibition percentage of E. coli bacteria was decreased after 80 min to be the lowest value.
    Matched MeSH terms: Escherichia coli/drug effects
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