Displaying publications 41 - 60 of 823 in total

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  1. Fulltext A multicentre study to determine the in vitro efficacy of flomoxef against extended-spectrum beta-lactamase producing Escherichia coli in Malaysia
    Yap PSX, Chong CW, Ponnampalavanar S, Ramli R, Harun A, Tengku Jamaluddin TZM, et al.
    PeerJ, 2023;11:e16393.
    PMID: 38047021 DOI: 10.7717/peerj.16393
    BACKGROUND: The high burden of extended-spectrum beta-lactamase-producing (ESBL)-producing Enterobacterales worldwide, especially in the densely populated South East Asia poses a significant threat to the global transmission of antibiotic resistance. Molecular surveillance of ESBL-producing pathogens in this region is vital for understanding the local epidemiology, informing treatment choices, and addressing the regional and global implications of antibiotic resistance.

    METHODS: Therefore, an inventory surveillance of the ESBL-Escherichia coli (ESBL-EC) isolates responsible for infections in Malaysian hospitals was conducted. Additionally, the in vitro efficacy of flomoxef and other established antibiotics against ESBL-EC was evaluated.

    RESULTS: A total of 127 non-repetitive ESBL-EC strains isolated from clinical samples were collected during a multicentre study performed in five representative Malaysian hospitals. Of all the isolates, 33.9% were isolated from surgical site infections and 85.8% were hospital-acquired infections. High rates of resistance to cefotaxime (100%), cefepime (100%), aztreonam (100%) and trimethoprim-sulfamethoxazole (100%) were observed based on the broth microdilution test. Carbapenems remained the most effective antibiotics against the ESBL-EC, followed by flomoxef. Antibiotic resistance genes were identified by PCR. The blaCTX-M-1 was the most prevalent ESBL gene, with 28 isolates (22%) harbouring blaCTX-M-1 only, 27 isolates (21.3%) co-harbouring blaCTX-M-1 and blaTEM, and ten isolates (7.9%) co-harbouring blaCTX-M-1, blaTEM and blaSHV. A generalised linear model showed significant antibacterial activity of imipenem against different types of infection. Besides carbapenems, this study also demonstrated a satisfactory antibacterial activity of flomoxef (81.9%) on ESBL-EC, regardless of the types of ESBL genes.

    Matched MeSH terms: Escherichia coli/genetics
  2. Preparation, characterization, immobilization, and molecular docking analysis of a novel detergent-stable subtilisin-like serine protease from Streptomyces mutabilis strain TN-X30
    Mechri S, Allala F, Bouacem K, Hasnaoui I, Gwaithan H, Chalbi TB, et al.
    Int J Biol Macromol, 2022 Dec 01;222(Pt A):1326-1342.
    PMID: 36242508 DOI: 10.1016/j.ijbiomac.2022.09.161
    We recently described the production of a detergent-biocompatible crude protease from Streptomyces mutabilis strain TN-X30. Here, we describe the purification, characterization, and immobilization of the serine alkaline protease (named SPSM), as well as the cloning, sequencing, and over-expression of its corresponding gene (spSM). Pure enzyme was obtained after ammonium sulphate precipitation followed by heat-treatment and Sephacryl® S-200 column purification. The sequence of the first 26 NH2-terminal residues of SPSM showed a high sequence identity to subtilisin-like serine proteases produced by actinobacteria. The spSM gene was heterologously expressed in Escherichia coli BL21(DE3)pLysS and E. coli BL21-AI™ strains using pTrc99A (rSPSM) and Gateway™ pDEST™ 17 [(His)6-tagged SPSM] vectors, respectively. Results obtained indicated that the (His)6-tagged SPSM showed the highest stability. The SPSM was immobilized using encapsulation and adsorption-encapsulation approaches and three different carriers. Features of SPSM in soluble and immobilized forms were analyzed by Fourier transform infrared (FTIR) spectroscopy in attenuated total reflection (ATR) mode, X-ray diffraction (XRD), zeta potential measurements, and field emission scanning electron microscopy (FE-SEM). The white clay and kaolin used in this study are eco-friendly binders to alginate-SPSM and show great potential for application of the immobilized SPSM in various industries. Molecular modeling and docking of N-succinyl-l-Phe-l-Ala-l-Ala-l-Phe-p-nitroanilide in the active site of SPSM revealed the involvement of 21 amino acids in substrate binding.
    Matched MeSH terms: Escherichia coli/genetics; Escherichia coli/metabolism
  3. Fulltext Exploiting reverse vaccinology approach for the design of a multiepitope subunit vaccine against the major SARS-CoV-2 variants
    Campos DMO, Silva MKD, Barbosa ED, Leow CY, Fulco UL, Oliveira JIN
    Comput Biol Chem, 2022 Dec;101:107754.
    PMID: 36037724 DOI: 10.1016/j.compbiolchem.2022.107754
    The current COVID-19 pandemic, an infectious disease caused by the novel coronavirus (SARS-CoV-2), poses a threat to global health because of its high rate of spread and death. Currently, vaccination is the most effective method to prevent the spread of this disease. In the present study, we developed a novel multiepitope vaccine against SARS-CoV-2 containing Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), and Omicron (BA.1) variants. To this end, we performed a robust immunoinformatics approach based on multiple epitopes of the four structural proteins of SARS-CoV-2 (S, M, N, and E) from 475 SARS-CoV-2 genomes sequenced from the regions with the highest number of registered cases, namely the United States, India, Brazil, France, Germany, and the United Kingdom. To investigate the best immunogenic epitopes for linear B cells, cytotoxic T lymphocytes (CTL), and helper T lymphocytes (HTL), we evaluated antigenicity, allergenicity, conservation, immunogenicity, toxicity, human population coverage, IFN-inducing, post-translational modifications, and physicochemical properties. The tertiary structure of a vaccine prototype was predicted, refined, and validated. Through docking experiments, we evaluated its molecular coupling to the key immune receptor Toll-Like Receptor 3 (TLR3). To improve the quality of docking calculations, quantum mechanics/molecular mechanics calculations (QM/MM) were used, with the QM part of the simulations performed using the density functional theory formalism (DFT). Cloning and codon optimization were performed for the successful expression of the vaccine in E. coli. Finally, we investigated the immunogenic properties and immune response of our SARS-CoV-2 multiepitope vaccine. The results of the simulations show that administering our prototype three times significantly increases the antibody response and decreases the amount of antigens. The proposed vaccine candidate should therefore be tested in clinical trials for its efficacy in neutralizing SARS-CoV-2.
    Matched MeSH terms: Escherichia coli
  4. Early-onset sepsis in Malaysian neonatal intensive care units
    Boo NY, Ang EBK, Neoh SH, Ang EL, Chee SC
    Malays J Pathol, 2022 Dec;44(3):443-459.
    PMID: 36591712
    OBJECTIVES: To determine the incidence, causative pathogens, morbidities, mortality, and risk factors associated with blood culture-positive early-onset sepsis (EOS, ≤72 hours of age) in symptomatic neonates admitted to the neonatal intensive care units (NICUs) of a middle-income country.

    STUDY DESIGN: Retrospective cohort study using data submitted prospectively to the Malaysian National Neonatal Registry (MNNR).

    SETTING: 44 Malaysian NICUs.

    PARTICIPANTS: All neonates born in 2015- 2020.

    RESULTS: EOS was reported in 991 neonates. The annual incidence of EOS increased from 0.46 to 0.49/1000 livebirths over the six years. The most common pathogen was Streptococcus agalactiae or Group B haemolytic streptococcus (GBS) (n=388, 39.2%), followed by Escherichia coli (E. coli) (n=80, 8.1%), Klebsiella spp (n=73, 7.4%), coagulase negative staphylococcus (CONS) (n=73, 7.4%), Pseudomonas spp (n=44, 4.4%) and methicillin-sensitive Staphylococcus aureus (n=34, 3.4%). The incidence of EOS due to GBS increased from 0.17 to 0.22/1000 livebirths. Morbidities and mortality were higher in those with EOS than without EOS. Multiple logistic regression analysis showed that Indian ethnic group, chorioamnionitis, gestation≥37weeks, female, spontaneous vaginal delivery, instrumental delivery, and surfactant therapy were significantly associated with increased risk of EOS due to GBS. Four factors were significantly associated with increased risk of non-GBS EOS (outborns, birthweight lt;1000 g, vaginal delivery, and surfactant therapy). Early continuous positive airway pressure was associated with significantly lower risk of EOS.

    CONCLUSION: The incidence of EOS showed an increasing trend in Malaysian NICUs. GBS was the most common causative pathogen. Several modifiable risk factors associated with EOS have been identified.

    Matched MeSH terms: Escherichia coli*
  5. Fulltext In Vitro Influence of ZnO, CrZnO, RuZnO, and BaZnO Nanomaterials on Bacterial Growth
    Abdallah EM, Modwi A, Al-Mijalli SH, Mohammed AE, Idriss H, Omar AS, et al.
    Molecules, 2022 Nov 28;27(23).
    PMID: 36500402 DOI: 10.3390/molecules27238309
    In this work, ZnO, CrZnO, RuZnO, and BaZnO nanomaterials were synthesized and characterized in order to study their antibacterial activity. The agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays were used to determine the antibacterial activity of the fabricated nanomaterials against Staphylococcus aureus ATCC 29213, Escherichia coli ATCC35218, Klebsiella pneumoniae ATCC 7000603, and Pseudomonas aeruginosa ATCC 278533. The well-diffusion test revealed significant antibacterial activity against all investigated bacteria when compared to vancomycin at a concentration of 1 mg/mL. The most susceptible bacteria to BaZnO, RuZnO, and CrZnO were Staphylococcus aureus (15.5 ± 0.5 mm), Pseudomonas aeruginosa (19.2 ± 0.5 mm), and Pseudomonas aeruginosa (19.7 ± 0.5), respectively. The MIC values indicated that they were in the range of 0.02 to 0.2 mg/mL. The MBC values showed that the tested bacteria's growth could be inhibited at concentrations ranging from 0.2 to 2.0 mg/mL. According to the MBC/MIC ratio, BaZnO, RuZnO, and CrZnO exhibit bacteriostatic effects and may target bacterial protein synthesis based on the results of the tolerance test. This study shows the efficacy of the above-mentioned nanoparticles on bacterial growth. Further biotechnological and toxicological studies on the nanoparticles fabricated here are recommended to benefit from these findings.
    Matched MeSH terms: Escherichia coli
  6. Compressed Hydrogen-Induced Synthesis of Quaternary Trimethyl Chitosan-Silver Nanoparticles with Dual Antibacterial and Antifungal Activities
    Alli YA, Ejeromedoghene O, Oladipo A, Adewuyi S, Amolegbe SA, Anuar H, et al.
    ACS Appl Bio Mater, 2022 Nov 21;5(11):5240-5254.
    PMID: 36270024 DOI: 10.1021/acsabm.2c00670
    Quaternary Trimethyl Chitosan (QTMC) and QTMC-Silver Nanoparticles (QTMC-AgNPs) have been synthesized, characterized, and tested as antibacterial agents against Staphylococcus aureus, Escherichia coli, and two plant fungi (Sclerotium rolfsil and Fusarium oxysporum). The as-prepared water-soluble QTMC was in situ reacted with silver nitrate in the presence of clean compressed hydrogen gas (3 bar) as a reducing agent to produce QTMC-AgNPs. UV-vis, ATR-FTIR, HR-TEM/SEM, XPS, DLS, XRD, and TGA/DTG were employed to assess the optical response, morphology/size, surface chemistry, particle size distribution, crystal nature, and thermal stability of the synthesized QTMC-AgNPs, respectively. The as-prepared QTMC-AgNPs were quasi-spherical in shape with an average particle size of 12.5 nm, as determined by ImageJ software utilizing HR-TEM images and further validated by DLS analysis. The development of crystalline nanoparticles was confirmed by the presence of distinct and consistent lattice fringes with an approximate interplanar d-spacing of 2.04 nm in QTMC-AgNPs. The QTMC-AgNPs exhibited significant antibacterial activity with a clear zone of inhibition of 30 mm and 26 mm around the disks against E. coli and S. aureus, respectively. In addition, QTMC-AgNPs showed highly efficient antifungal activity with 100% and 76.67% growth inhibition against two plant pathogens, S. rolfsii and F. oxysporum, respectively, whereas QTMC revealed no impact. Overall, QTMC-AgNPs showed a promising therapeutic potential and,thus, can be considered for drug design rationale.
    Matched MeSH terms: Escherichia coli
  7. Prominent bactericidal characteristics of silver-copper nanocomposites produced via pulse laser ablation
    Alhajj M, Aziz MSA, Huyop F, Salim AA, Sharma S, Ghoshal SK
    Biomater Adv, 2022 Nov;142:213136.
    PMID: 36206587 DOI: 10.1016/j.bioadv.2022.213136
    This paper reports the characterization and antibacterial performance evaluation of some spherical and stable crystalline silver (Ag)/copper (Cu) nanocomposites (Ag-CuNCs) prepared in deionized water (DIW) using pulse laser ablation in liquid (PLAL) method. The influence of various laser fluences (LFs) on the structural, morphological, optical and antibacterial properties of these NCs were determined. The UV-Vis absorbance of these NCs at 403 nm and 595 nm was gradually increased accompanied by a blue shift. XRD patterns disclosed the nucleation of highly crystalline Ag-CuNCs with their face centered cubic lattice structure. TEM images showed the existence of spherical NCs with size range of 3-20 nm and lattice fringe spacing of approximately 0.145 nm. EDX profiles of Ag-CuNCs indicated their high purity. The antibacterial effectiveness of the Ag-CuNCs was evaluated by the inhibition zone diameter (IZD) and optical density (OD600) tests against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. The proposed NCs revealed the IZD values in the range of 22-26 mm and 20-25 mm when tested against E. coli and S. aureus bacteria, respectively. The Ag-CuNCs prepared at LF of 14.15 J/cm2 revealed the best bactericidal activity. It is established that by controlling the laser fluence the bactericidal effectiveness of the Ag-CuNCs can be tuned.
    Matched MeSH terms: Escherichia coli
  8. Fulltext Antibiotic Resistance during COVID-19: A Systematic Review
    Sulayyim HJA, Ismail R, Hamid AA, Ghafar NA
    Int J Environ Res Public Health, 2022 Sep 21;19(19).
    PMID: 36231256 DOI: 10.3390/ijerph191911931
    One of the public health issues faced worldwide is antibiotic resistance (AR). During the novel coronavirus (COVID-19) pandemic, AR has increased. Since some studies have stated AR has increased during the COVID-19 pandemic, and others have stated otherwise, this study aimed to explore this impact. Seven databases-PubMed, MEDLINE, EMBASE, Scopus, Cochrane, Web of Science, and CINAHL-were searched using related keywords to identify studies relevant to AR during COVID-19 published from December 2019 to May 2022, according to PRISMA guidelines. Twenty-three studies were included in this review, and the evidence showed that AR has increased during the COVID-19 pandemic. The most commonly reported resistant Gram-negative bacteria was Acinetobacterbaumannii, followed by Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. A. baumannii and K. pneumonia were highly resistant to tested antibiotics compared with E. coli and P. aeruginosa. Moreover, K. pneumonia showed high resistance to colistin. Commonly reported Gram-positive bacteria were Staphylococcus aureus and Enterococcus faecium. The resistance of E. faecium to ampicillin, erythromycin, and Ciprofloxacin was high. Self-antibiotic medication, empirical antibiotic administration, and antibiotics prescribed by general practitioners were the risk factors of high levels of AR during COVID-19. Antibiotics' prescription should be strictly implemented, relying on the Antimicrobial Stewardship Program (ASP) and guidelines from the World Health Organization (WHO) or Ministry of Health (MOH).
    Matched MeSH terms: Escherichia coli
  9. Exploration of cassava plant xylem for water treatment: preparation, characterization and filtration capability
    Hashim A, Hashim NA, Mohd Junaidi MU, Kamarudin D, Hussain MA
    Water Sci Technol, 2022 Sep;86(5):1055-1065.
    PMID: 36358045 DOI: 10.2166/wst.2022.253
    Flood is among the natural disasters that commonly happened in Malaysia every year. During the flood, victims faced clean water shortages and deterioration of the environment resulting in long waiting times for aid to access. Hence, affordable and efficient filters are needed to supply clean water in the affected areas. Application of xylem tissue inside plant stem has the potential as a filter for water filtration. This research focuses on xylem tissue in Malaysian tropical plants from cassava stem. Cassava stems were prepared in a small-scale set-up as the xylem was used as a filter. Effects of cross-sectional area and hydrostatic pressure were analyzed and the results showed a directly proportional relationship with permeate flow rate. Upon filtration with red dye solution, total dye removal was achieved using a xylem with a minimal length of 3 cm and onwards. While for bacteria removal, E. coli bacteria have been removed when tested with a bacteria count plate. Thus, this study demonstrated the potential of the xylem tissue of the cassava plant as affordable and available natural raw materials to be used as water filters during an emergency.
    Matched MeSH terms: Escherichia coli
  10. Enhanced water flux and bacterial resistance in cellulose acetate membranes with quaternary ammoniumpropylated polysilsesquioxane
    Pandey RP, Kallem P, Rasheed PA, Mahmoud KA, Banat F, Lau WJ, et al.
    Chemosphere, 2022 Feb;289:133144.
    PMID: 34863730 DOI: 10.1016/j.chemosphere.2021.133144
    An enhanced water flux and anti-fouling nanocomposite ultrafiltration membrane based on quaternary ammoniumpropylated polysilsesquioxane (QAPS)/cellulose acetate (QAPS@CA) was fabricated by in situ sol-gel processing via phase inversion followed by quaternization with methyl iodide (CH3I). Membrane characterizations were performed based on the contact angle, FTIR, SEM, and TGA properties. Membrane separation performance was assessed in terms of pure water flux, rejection, and fouling resistance. The 7%QAPS@CA nanocomposite membrane showed an increased wettability (46.6° water contact angle), water uptake (113%) and a high pure water permeability of ∼370 L m-2 h-1 bar-1. Furthermore, the 7%QAPS@CA nanocomposite membrane exhibited excellent bactericidal properties (∼97.5% growth inhibition) against Escherichia coli (E. coli) compared to the bare CA membrane (0% growth inhibition). The 7%QAPS@CA nanocomposite membrane can be recommended for water treatment and biomedical applications.
    Matched MeSH terms: Escherichia coli*
  11. Effects of immunostimulators of microbial origin on T cells of pigs vaccinated with attenuated vaccine against Aujeszky's disease
    Andrišić M, Žarković I, Šandor K, Vujnović A, Perak Junaković E, Bendelja K, et al.
    Vet Immunol Immunopathol, 2022 Jan;243:110365.
    PMID: 34920287 DOI: 10.1016/j.vetimm.2021.110365
    Aujeszky's disease (AD) is a viral infectious disease caused by Suid herpesvirus 1 (SuHV-1). Vaccination and eradication of AD in domestic pigs is possible using marker vaccines with attenuated or inactivated SuHV-1, or subunit vaccines. However, vaccines with attenuated SuHV-1 have shown to be more potent in inducing strong cell-mediated immune response. The studies have shown that Parapoxvirus ovis, as well as Propionibacterium granulosum with lipopolysacharides (LPS) of Escherichia coli have pronounced immunomodulatory effects and that in combination with the vaccines can induce stronger humoral and cellular immune responses than use of vaccines alone. In our study distribution of peripheral blood T cell subpopulations was analysed after administration of vaccine alone (attenuated SuHV-1), immunostimulators (inactivated Parapoxvirus ovis or combination of an inactivated P. granulosum and detoxified LPS of E. coli) and combinations of vaccine with each immunostimulator to the 12-week old piglets. Throughout the study no significant changes were found in the proportions of γδ and most αβ T cell subpopulations analysed. However, on the seventh day of the study combination of an inactivated P. granulosum and LPS of E. coli with vaccine induced transient but significant increase of the proportions of CD4+CD8α+ and CD4-CD8α+ αβ T cells, that have been strongly associated with early protection of SuHV-1 infected pigs. Our findings indicate that combination of inactivated P. granulosum and detoxified E. coli LPS could be used for enhancement of a cellular immune response induced by vaccines against AD.
    Matched MeSH terms: Escherichia coli
  12. Fulltext Enhanced Thermal Stability and Synergistic Effects of Magnesium and Iron Borate Composites against Pathogenic Bacteria
    Ahmad P, Khandaker MU, Khan A, Rehman F, Din SU, Ali H, et al.
    Biomed Res Int, 2022;2022:3605054.
    PMID: 36420094 DOI: 10.1155/2022/3605054
    A simple process based on the dual roles of both magnesium oxide (MgO) and iron oxide (FeO) with boron (B) as precursors and catalysts has been developed for the synthesis of borate composites of magnesium and iron (Mg2B2O5-Fe3BO6) at 1200°C. The as-synthesized composites can be a single material with the improved and collective properties of both iron borates (Fe3BO6) and magnesium borates (Mg2B2O5). At higher temperatures, the synthesized Mg2B2O5-Fe3BO6 composite is found thermally more stable than the single borates of both magnesium and iron. Similarly, the synthesized composites are found to prevent the growth of both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) pathogenic bacteria on all the tested concentrations. Moreover, the inhibitory effect of the synthesized composite increases with an increase in concentration and is more pronounced against S. aureus as compared to E. coli.
    Matched MeSH terms: Escherichia coli
  13. Fulltext High prevalence of antimicrobial resistance and multidrug resistance among bacterial isolates from diseased pets: Retrospective laboratory data (2015-2017)
    Haulisah NA, Hassan L, Jajere SM, Ahmad NI, Bejo SK
    PLoS One, 2022;17(12):e0277664.
    PMID: 36477195 DOI: 10.1371/journal.pone.0277664
    Laboratory surveillance and the monitoring of antimicrobial resistance (AMR) trends and patterns among local isolates have been highly effective in providing comprehensive information for public health decision-making. A total of 396 cases along with 449 specimens were received for antibiotic susceptibility testing at a public university veterinary diagnostic laboratory in Malaysia between 2015 and 2017. Escherichia coli was the most frequently isolated (n = 101, 13%) bacteria, followed by Staphylococcus pseudintermedius (n = 97, 12%) and Streptococcus canis (n = 62, 8%). In cats, S. pseudintermedius isolates were highly resistant to azithromycin (90%), while the E. coli isolates were highly resistant to doxycycline (90%), tetracycline (81%), and cephalexin (75%). About 55% of S. pseudintermedius and 82% of E. coli were multi-drug resistant (MDR). In dogs, S. intermedius isolates were highly resistant to aminoglycosides neomycin (90.9%) and gentamicin (84.6%), and tetracycline (75%). Whereas the E. coli isolates were highly resistant to cephalexin (82.1%) and amoxicillin/clavulanic acid (76.5%). MDR was observed in 60% of S. intermedius and 72% of E. coli from dogs. Generally, the bacterial isolates from cats demonstrated higher levels of resistance to multiple antibiotics compared to those from dogs.
    Matched MeSH terms: Escherichia coli*
  14. A Point Prevalence Study of the Use of Antibiotics in Six Tertiary Care Hospitals in the Kathmandu Valley, Nepal
    Jha N, Thapa B, Pathak SB, Pandey A, Pokhrel S, Shankar PR, et al.
    Kathmandu Univ Med J (KUMJ), 2022;20(79):351-358.
    PMID: 37042379
    Background Point prevalence survey (PPS) on antibiotic use developed by the WHO has already been used in many hospitals globally. Objective To obtain information on antibiotic prescribtion using point prevalence survey methodology in six private hospitals in the Kathmandu valley. Method This descriptive cross-sectional study was completed during 20th July to 28th July 2021 using point prevalence survey methodology. The study was conducted among inpatients admitted at or before 8:00 AM on the day of survey in various wards. Data was presented as frequencies and percentages. Result Maximum number of patients were above 60 years [34 (18.7%)]. Number of male and female participants were equal [91 (50%)]. Only one antibiotic was used in 81 patients (44.5%) followed by two antibiotics in 71 (39%) patients. Duration of prophylactic antibiotic use was one day in 66 (63.7%) patients. Blood, urine, sputum, and wound swabs were the common samples for culture. Cultures were positive for 17 (24.7%) samples. The common organisms isolated were E. Coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. Ceftriaxone was the most used antibiotic. Drug and therapeutics, infection control committee and pharmacovigilance activities were present in 3/6 (50%) study sites. Antimicrobial stewardship was present in 3/6 (50%) and microbiological services was present in all hospitals. Antibiotic formulary and antibiotic guideline were present in 4/6 sites and facilities to audit or review surgical antibiotic prophylaxis choice in 2/6 (33.3%) sites, facility to monitor antibiotic use in 4/6 (66.6%) and cumulative antibiotic susceptibility reports in 2/6 (33.3%) study sites. Conclusion Ceftriaxone was the most used antibiotic. E. Coli, Pseudomonas aeruginosa and Klebsiella pneumonia were the commonly isolated organisms. Not all parameters for infrastructure, policy and practice and monitoring and feedback were present at the study sites. KEY WORDS.
    Matched MeSH terms: Escherichia coli*
  15. Fulltext Thermodynamics of semi-specific ligand recognition: the binding of dipeptides to the E.coli dipeptide binding protein DppA
    Zainol MKM, Linforth RJC, Winzor DJ, Scott DJ
    Eur Biophys J, 2021 Dec;50(8):1103-1110.
    PMID: 34611772 DOI: 10.1007/s00249-021-01572-y
    This investigation of the temperature dependence of DppA interactions with a subset of three dipeptides (AA. AF and FA) by isothermal titration calorimetry has revealed the negative heat capacity ([Formula: see text]) that is a characteristic of hydrophobic interactions. The observation of enthalpy-entropy compensation is interpreted in terms of the increased structuring of water molecules trapped in a hydrophobic environment, the enthalpic energy gain from which is automatically countered by the entropy decrease associated with consequent loss of water structure flexibility. Specificity for dipeptides stems from appropriate spacing of designated DppA aspartate and arginine residues for electrostatic interaction with the terminal amino and carboxyl groups of a dipeptide, after which the binding pocket closes to become completely isolated from the aqueous environment. Any differences in chemical reactivity of the dipeptide sidechains are thereby modulated by their occurrence in a hydrophobic environment where changes in the structural state of entrapped water molecules give rise to the phenomenon of enthalpy-entropy compensation. The consequent minimization of differences in the value of ΔG0 for all DppA-dipeptide interactions thus provides thermodynamic insight into the biological role of DppA as a transporter of all dipeptides across the periplasmic membrane.
    Matched MeSH terms: Escherichia coli/metabolism; Escherichia coli Proteins*
  16. Bone tissue engineering potentials of 3D printed magnesium-hydroxyapatite in polylactic acid composite scaffolds
    Anita Lett J, Sagadevan S, Léonard E, Fatimah I, Motalib Hossain MA, Mohammad F, et al.
    Artif Organs, 2021 Dec;45(12):1501-1512.
    PMID: 34309044 DOI: 10.1111/aor.14045
    The primary role of bone tissue engineering is to reconcile the damaged bones and facilitate the speedy recovery of the injured bones. However, some of the investigated metallic implants suffer from stress-shielding, palpability, biocompatibility, etc. Consequently, the biodegradable scaffolds fabricated from polymers have gathered much attention from researchers and thus helped the tissue engineering sector by providing many alternative materials whose functionality is similar to that of natural bones. Herein, we present the fabrication and testing of a novel composite, magnesium (Mg)-doped hydroxyapatite (HAp) glazed onto polylactic acid (PLA) scaffolds where polyvinyl alcohol (PVA) used as a binder. For the composite formation, Creality Ender-3 pro High Precision 3D Printer with Shape tool 3D Technology on an FSD machine operated by Catia design software was employed. The composite has been characterized for the crystallinity (XRD), surface functionality (FTIR), morphology (FESEM), biocompatibility (hemolytic and protein absorption), and mechanical properties (stress-strain and maximum compressive strength). The powder XRD analysis confirmed the semicrystalline nature and intact structure of HAp even after doping with Mg, while FTIR studies for the successful formation of Mg-HAp/PVA@PLA composite. The FESEM provided analysis indicated for the 3D porous architecture and well-defined morphology to efficiently transport the nutrients, and the biocompatibility studies are supporting that the composite for blood compatible with the surface being suitable enough for the protein absorption. Finally, the composite's antibacterial activity (against Staphylococcus aureus and Escherichia coli) and the test of mechanical properties supported for the enhanced inhibition of active growth of microorganisms and maximum compressive strength, respectively. Based on the research outcomes of biocompatibility, antibacterial activity, and mechanical resistance, the fabricated Mg-HAp/PVA@PLA composite suits well as a promising biomaterial platform for orthopedic applications by functioning towards the open reduction internal fixation of bone fractures and internal repairs.
    Matched MeSH terms: Escherichia coli/drug effects
  17. 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
  18. Fulltext Maternal and umbilical cord blood polymorphonuclear leukocytes showed moderate oxidative burst at phagocytosis of Gardnerella vaginalis
    Swaminathan A, Abd Aziz NH, Ayub NA, Wong KK, Cheah FC
    BMC Res Notes, 2021 Nov 22;14(1):420.
    PMID: 34809696 DOI: 10.1186/s13104-021-05842-y
    OBJECTIVE: Pregnant women with bacterial vaginosis due to Gardnerella vaginalis (GV) infection presents with a wide-ranging disease symptomatology. We speculate this may be due to interaction that varies between host immune response and the pathogen. We studied the oxidative burst in polymorphonuclear leukocytes (PMNL)s from maternal blood (MB) and cord blood (CB) upon phagocytosis of GV and compared against E. coli and Group B Streptococcus (GBS).

    RESULTS: The PHAGOBURST™ assay detects fluorescence from oxidized dihydrorhodamine during oxidative burst. The average percentage of PMNL showing oxidative burst was almost two-fold greater with GBS (99.5%) and E. coli (98.2%) than GV (56.9%) (p  coli but comparable to GBS. The MFI of CB PMNL (1580 ± 245.8) was significantly higher than MB PMNL (1198 ± 262.1) with GV, p  = 0.031. The live-cell imaging showed neutrophil oxidative burst upon phagocytosis of GV produces hypochlorous acid (HOCl). Overall, the HOCL-mediated microbicidal activity against GV is more variable and less robust than E. coli and GBS, especially in maternal than CB PMNL.

    Matched MeSH terms: Escherichia coli
  19. 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
  20. Novel Ag/cellulose-doped CeO2 quantum dots for efficient dye degradation and bactericidal activity with molecular docking study
    Ikram M, Hayat S, Imran M, Haider A, Naz S, Ul-Hamid A, et al.
    Carbohydr Polym, 2021 Oct 01;269:118346.
    PMID: 34294353 DOI: 10.1016/j.carbpol.2021.118346
    In the present study, the novel Ag/cellulose nanocrystal (CNC)-doped CeO2 quantum dots (QDs) with highly efficient catalytic performance were synthesized using one pot co-precipitation technique, which were then applied in the degradation of methylene blue and ciprofloxacin (MBCF) in wastewater. Catalytic activity against MBCF dye was significantly reduced (99.3%) for (4%) Ag dopant concentration in acidic medium. For Ag/CNC-doped CeO2 vast inhibition domain of G-ve was significantly confirmed as (5.25-11.70 mm) and (7.15-13.60 mm), while medium- to high-concentration of CNC levels were calculated for G + ve (0.95 nm, 1.65 mm), respectively. Overall, (4%) Ag/CNC-doped CeO2 revealed significant antimicrobial activity against G-ve relative to G + ve at both concentrations, respectively. Furthermore, in silico molecular docking studies were performed against selected enzyme targets dihydrofolate reductase (DHFR), dihydropteroate synthase (DHPS), and DNA gyrase belonging to folate and nucleic acid biosynthetic pathway, respectively to rationalize possible mechanism behind bactericidal potential of CNC-CeO2 and Ag/CNC-CeO2.
    Matched MeSH terms: Escherichia coli/drug effects; Escherichia coli/enzymology
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