Displaying publications 41 - 58 of 58 in total

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  1. Koitabashi T, Vuddhakul V, Radu S, Morigaki T, Asai N, Nakaguchi Y, et al.
    Microbiol. Immunol., 2006;50(2):135-48.
    PMID: 16490932
    Nine Escherichia coli O157: H7/- strains isolated primarily from non-clinical sources in Thailand and Japan carried the stx(2) gene but did not produce Stx2 toxin in a reversed passive latex agglutination (RPLA) assay. A strain (EDL933) bearing a stx(2) phage (933W) was compared to a strain (Thai-12) that was Stx2-negative but contained the stx(2) gene. To study the lack of Stx2 production, the Thai-12 stx(2) gene and its upstream nucleotide sequence were analyzed. The Thai-12 stx(2) coding region was intact and Stx2 was expressed from a cloned stx(2) gene using a plasmid vector and detected using RPLA. A lacZ fusion analysis found the Thai-12 stx(2) promoter non-functional. Because the stx(2) gene is downstream of the late promoter in the stx(2) phage genome, the antitermination activity of Q protein is essential for strong stx(2) transcription. Thai-12 had the q gene highly homologous to that of Phi21 phage but not to the 933W phage. High-level expression of exogenous q genes demonstrated Q antitermination activity was weak in Thai-12. Replication of stx(2) phage was not observed in Stx2-negative strains. The q-stx(2) gene sequence of Thai-12 was well conserved in all Stx2-negative strains. A PCR assay to detect the Thai-12 q-stx(2) sequence demonstrated that 30% of O157 strains from marketed Malaysian beef carried this sequence and they produced little or no Stx2. These results suggest that stx(2)-positive O157 strains that produce little or no Stx2 may be widely distributed in the Asian environment.
    Matched MeSH terms: Escherichia coli Infections/microbiology*
  2. Beatson SA, Ben Zakour NL, Totsika M, Forde BM, Watts RE, Mabbett AN, et al.
    Infect Immun, 2015 May;83(5):1749-64.
    PMID: 25667270 DOI: 10.1128/IAI.02810-14
    Urinary tract infections (UTIs) are among the most common infectious diseases of humans, with Escherichia coli responsible for >80% of all cases. One extreme of UTI is asymptomatic bacteriuria (ABU), which occurs as an asymptomatic carrier state that resembles commensalism. To understand the evolution and molecular mechanisms that underpin ABU, the genome of the ABU E. coli strain VR50 was sequenced. Analysis of the complete genome indicated that it most resembles E. coli K-12, with the addition of a 94-kb genomic island (GI-VR50-pheV), eight prophages, and multiple plasmids. GI-VR50-pheV has a mosaic structure and contains genes encoding a number of UTI-associated virulence factors, namely, Afa (afimbrial adhesin), two autotransporter proteins (Ag43 and Sat), and aerobactin. We demonstrated that the presence of this island in VR50 confers its ability to colonize the murine bladder, as a VR50 mutant with GI-VR50-pheV deleted was attenuated in a mouse model of UTI in vivo. We established that Afa is the island-encoded factor responsible for this phenotype using two independent deletion (Afa operon and AfaE adhesin) mutants. E. coli VR50afa and VR50afaE displayed significantly decreased ability to adhere to human bladder epithelial cells. In the mouse model of UTI, VR50afa and VR50afaE displayed reduced bladder colonization compared to wild-type VR50, similar to the colonization level of the GI-VR50-pheV mutant. Our study suggests that E. coli VR50 is a commensal-like strain that has acquired fitness factors that facilitate colonization of the human bladder.
    Matched MeSH terms: Escherichia coli Infections/microbiology*
  3. Ahmad KA, Mohanmmed AS, Abas F, Chin SC
    Virol Sin, 2015 Feb;30(1):73-5.
    PMID: 25662886 DOI: 10.1007/s12250-014-3541-8
    Matched MeSH terms: Escherichia coli Infections/microbiology*
  4. Nhu NTK, Phan MD, Peters KM, Lo AW, Forde BM, Min Chong T, et al.
    mBio, 2018 08 21;9(4).
    PMID: 30131362 DOI: 10.1128/mBio.01462-18
    Curli are bacterial surface-associated amyloid fibers that bind to the dye Congo red (CR) and facilitate uropathogenic Escherichia coli (UPEC) biofilm formation and protection against host innate defenses. Here we sequenced the genome of the curli-producing UPEC pyelonephritis strain MS7163 and showed it belongs to the highly virulent O45:K1:H7 neonatal meningitis-associated clone. MS7163 produced curli at human physiological temperature, and this correlated with biofilm growth, resistance of sessile cells to the human cationic peptide cathelicidin, and enhanced colonization of the mouse bladder. We devised a forward genetic screen using CR staining as a proxy for curli production and identified 41 genes that were required for optimal CR binding, of which 19 genes were essential for curli synthesis. Ten of these genes were novel or poorly characterized with respect to curli synthesis and included genes involved in purine de novo biosynthesis, a regulator that controls the Rcs phosphorelay system, and a novel repressor of curli production (referred to as rcpA). The involvement of these genes in curli production was confirmed by the construction of defined mutants and their complementation. The mutants did not express the curli major subunit CsgA and failed to produce curli based on CR binding. Mutation of purF (the first gene in the purine biosynthesis pathway) and rcpA also led to attenuated colonization of the mouse bladder. Overall, this work has provided new insight into the regulation of curli and the role of these amyloid fibers in UPEC biofilm formation and pathogenesis.IMPORTANCE Uropathogenic Escherichia coli (UPEC) strains are the most common cause of urinary tract infection, a disease increasingly associated with escalating antibiotic resistance. UPEC strains possess multiple surface-associated factors that enable their colonization of the urinary tract, including fimbriae, curli, and autotransporters. Curli are extracellular amyloid fibers that enhance UPEC virulence and promote biofilm formation. Here we examined the function and regulation of curli in a UPEC pyelonephritis strain belonging to the highly virulent O45:K1:H7 neonatal meningitis-associated clone. Curli expression at human physiological temperature led to increased biofilm formation, resistance of sessile cells to the human cationic peptide LL-37, and enhanced bladder colonization. Using a comprehensive genetic screen, we identified multiple genes involved in curli production, including several that were novel or poorly characterized with respect to curli synthesis. In total, this study demonstrates an important role for curli as a UPEC virulence factor that promotes biofilm formation, resistance, and pathogenesis.
    Matched MeSH terms: Escherichia coli Infections/microbiology
  5. Lai YM, Zaw MT, Shamsudin SB, Lin Z
    J Infect Dev Ctries, 2016 Oct 31;10(10):1053-1058.
    PMID: 27801366 DOI: 10.3855/jidc.6944
    INTRODUCTION: Uropathogenic virulence factors have been identified by comparing the prevalence of these among urinary tract isolates and environmental strains. The uropathogenic-specific protein (USP) gene is present on the pathogenicity island (PAI) of uropathogenic Escherichia coli (UPEC) and, depending on its two diverse gene types and the sequential patterns of three open reading frame units (orfUs) following it, there is a method to characterize UPEC epidemiologically called PAIusp subtyping.
    METHODOLOGY: A total of 162 UPEC isolates from Sabah, Malaysia, were tested for the presence of the usp gene and the sequential patterns of three orfUs following it using polymerase chain reaction (PCR). In addition, by means of triplex PCR, the prevalence of the usp gene was compared with other two VFs of UPEC, namely alpha hemolysin (α-hly) and cytotoxic necrotizing factor (cnf-1) genes encoding two toxins.
    RESULTS: The results showed that the usp gene was found in 78.40% of UPEC isolates, indicating that its prevalence was comparable to that found in a previous study in Japan. The two or three orfUs were also associated with the usp gene in this study. All the PAIusp subtypes observed in Japan were present in this study, while subtype IIa was the most common in both studies. The usp gene was observed in a higher percentage of isolates when compared with α-hly and cnf-1 genes.
    CONCLUSIONS: The findings in Japan and Sabah, East Malaysia, were similar, indicating that PAIusp subtyping is applicable to the characterization of UPEC strains epidemiologically elsewhere in the world.
    Matched MeSH terms: Escherichia coli Infections/microbiology
  6. Pan F, Li Z, Gong H, Petkov JT, Lu JR
    J Colloid Interface Sci, 2018 Dec 01;531:18-27.
    PMID: 30015167 DOI: 10.1016/j.jcis.2018.07.031
    Surfactants are multifunctional molecules widely used in personal care and healthcare formulations to cleanse, help disperse active ingredients (e.g., forming emulsions) and stabilise products. With increasing demands on improving biosafety, there is now mounting pressure to understand how different surfactants elicit toxicities at molecular and cellular levels. This work reports the membrane-lytic behaviour of a group of sulphonated methyl ester (SME) surfactants together with representative conventional surfactants. All surfactants displayed the clear rise of lysis of the model lipid bilayer membranes around their CMCs, but the two ionic surfactants SDS and C12TAB even caused measurable lysis below their CMCs, with membrane-lytic actions increasing with monomer concentration. Furthermore, whilst ionic and nonionic surfactants could achieve full membrane lysis once above their CMCs, this ability was weak from the SME surfactants and decreased with increasing the acyl chain length. In contrast to the conventional anionic surfactants such as SDS and SLES, the protein solubilizing capability of the SME surfactants was also low. On the other hand, MTT assays against 3T3 fibroblast cells and human chondrocyte cells revealed high toxicity from SDS and C12TAB against the other surfactants studied, but the difference between SME and the rest of conventional surfactants was small. Similar behaviour was also observed in their bactericidal effect against E. coli and S. aureus. The trend is broadly consistent with their membrane-lytic behaviour, indicating little selectivity in their cytotoxicity and bactericidal action. These results thus reveal different toxicities implicated from different surfactant head groups. Increase in acyl chain length as observed from SME surfactants could help improve surfactant biocompatibility.
    Matched MeSH terms: Escherichia coli Infections/drug therapy
  7. Ariffin EY, Lee YH, Futra D, Tan LL, Karim NHA, Ibrahim NNN, et al.
    Anal Bioanal Chem, 2018 Mar;410(9):2363-2375.
    PMID: 29504083 DOI: 10.1007/s00216-018-0893-1
    A novel electrochemical DNA biosensor for ultrasensitive and selective quantitation of Escherichia coli DNA based on aminated hollow silica spheres (HSiSs) has been successfully developed. The HSiSs were synthesized with facile sonication and heating techniques. The HSiSs have an inner and an outer surface for DNA immobilization sites after they have been functionalized with 3-aminopropyltriethoxysilane. From field emission scanning electron microscopy images, the presence of pores was confirmed in the functionalized HSiSs. Furthermore, Brunauer-Emmett-Teller (BET) analysis indicated that the HSiSs have four times more surface area than silica spheres that have no pores. These aminated HSiSs were deposited onto a screen-printed carbon paste electrode containing a layer of gold nanoparticles (AuNPs) to form a AuNP/HSiS hybrid sensor membrane matrix. Aminated DNA probes were grafted onto the AuNP/HSiS-modified screen-printed electrode via imine covalent bonds with use of glutaraldehyde cross-linker. The DNA hybridization reaction was studied by differential pulse voltammetry using an anthraquinone redox intercalator as the electroactive DNA hybridization label. The DNA biosensor demonstrated a linear response over a wide target sequence concentration range of 1.0×10-12-1.0×10-2 μM, with a low detection limit of 8.17×10-14 μM (R2 = 0.99). The improved performance of the DNA biosensor appeared to be due to the hollow structure and rough surface morphology of the hollow silica particles, which greatly increased the total binding surface area for high DNA loading capacity. The HSiSs also facilitated molecule diffusion through the silica hollow structure, and substantially improved the overall DNA hybridization assay. Graphical abstract Step-by-step DNA biosensor fabrication based on aminated hollow silica spheres.
    Matched MeSH terms: Escherichia coli Infections/microbiology*
  8. Subramaniam G, Palasubramaniam S, Navaratnam P
    Indian J Med Microbiol, 2006 Jul;24(3):205-7.
    PMID: 16912441
    Escherichia coli isolates resistant to ceftazidime isolated in the University Malaya Medical Center (UMMC) Kuala Lumpur, Malaysia, between the years 1998 and 2000 were studied for extended-spectrum beta-lactamase (ESBL) production. All strains were analysed phenotypically and genotypically and found to be ESBL-producing organisms harbouring SHV-5 beta-lactamase. This was confirmed by PCR-SSCP and nucleotide sequencing of the blaSHV amplified gene. As there was no evidence of ESBL activity in E. coli prior to this, coupled with the fact that there was a predominance of SHV-5 beta-lactamases in Klebsiella pneumoniae isolates in UMMC, we postulate that the E. coli obtained the SHV-5 beta-lactamase genes by plasmid transfer from the ESBL-producing K. pneumoniae.
    Matched MeSH terms: Escherichia coli Infections/microbiology*
  9. Borkataki S, Katoch R, Goswami P, Bhat A, Chakraborty D
    Trop Biomed, 2021 Mar 01;38(1):86-93.
    PMID: 33797529 DOI: 10.47665/tb.38.1.015
    The study was aimed to evaluate the effectiveness of maggot therapy in healing of cutaneous infected wound in streptozotocin (STZ) induced diabetic Wistar rat. For live maggots, the sterilized eggs of Lucilia sericata were obtained from colonies established in laboratory. Diabetes model was established in 48 male Wister rat by intra-peritoneal injection of STZ at the dose of 60 mg/kg body-weight. Cutaneous wounds exposed with mixed colonies of bacteria like Staphylococcus aureus, E. coli and Pseudomonas aeruginosa were prepared in all rat. The animals equally divided in 4 groups with 12 rats each being presented as treatment group of control, antibiotic, maggot and maggot with antibiotic in combination. All treatments were done once and hold for 24 hours. Wound kinetics and bacterial bio burden were measured at weekly interval to till complete healing. Significant reduction in wound area with maximum contraction was found (>95%) in maggot treated group when compared to antibiotic treated (79%) and control (72%). In maggot as well as maggot and antibiotic in combination group showed early elimination of bacterial bio-burden 7.88±0.03log CFU/ml to 1.12±0.65log CFU/ml and 7.86±0.04) log CFU/ml to 1.54±0.52log CFU/ml respectively in three weeks of time. Early healing indication was also experienced on histomorphological examination of wounded tissue of maggot treated groups by early and better epithelialization, collagenation and neovascularization with complete healing of wound in three weeks in comparison to antibiotic and control respectively. However, the present study did not show any difference in healing of wound with use of maggot alone or in antibiotic combination. Live maggot of Lucilia sericata effectively lower bacterial bioburden and and accelerate healing of infected cutaneous wound in diabetic conditions.
    Matched MeSH terms: Escherichia coli Infections/therapy
  10. Butt J, Jenab M, Werner J, Fedirko V, Weiderpass E, Dahm CC, et al.
    Gut Microbes, 2021;13(1):1-14.
    PMID: 33874856 DOI: 10.1080/19490976.2021.1903825
    Experimental evidence has implicated genotoxic Escherichia coli (E. coli) and enterotoxigenic Bacteroides fragilis (ETBF) in the development of colorectal cancer (CRC). However, evidence from epidemiological studies is sparse. We therefore assessed the association of serological markers of E. coli and ETBF exposure with odds of developing CRC in the European Prospective Investigation into Nutrition and Cancer (EPIC) study.Serum samples of incident CRC cases and matched controls (n = 442 pairs) were analyzed for immunoglobulin (Ig) A and G antibody responses to seven E. coli proteins and two isoforms of the ETBF toxin via multiplex serology. Multivariable-adjusted conditional logistic regression analyses were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association of sero-positivity to E. coli and ETBF with CRC.The IgA-positivity of any of the tested E. coli antigens was associated with higher odds of developing CRC (OR: 1.42; 95% CI: 1.05-1.91). Dual-positivity for both IgA and IgG to E. coli and ETBF was associated with >1.7-fold higher odds of developing CRC, with a significant association only for IgG (OR: 1.75; 95% CI: 1.04, 2.94). This association was more pronounced when restricted to the proximal colon cancers (OR: 2.62; 95% CI: 1.09, 6.29) compared to those of the distal colon (OR: 1.24; 95% CI: 0.51, 3.00) (pheterogeneity = 0.095). Sero-positivity to E. coli and ETBF was associated with CRC development, suggesting that co-infection of these bacterial species may contribute to colorectal carcinogenesis. These findings warrant further exploration in larger prospective studies and within different population groups.
    Matched MeSH terms: Escherichia coli Infections/immunology
  11. Ugwu IC, Lee-Ching L, Ugwu CC, Okoye JOA, Chah KF
    Iran J Vet Res, 2020;21(3):180-187.
    PMID: 33178295
    Background: Avian pathogenic Escherichia coli (APEC) strains have been associated with various disease conditions in avian species due to virulence attributes associated with the organism.

    Aims: This study was carried out to determine the in vitro pathogenic characteristics and virulence encoding genes found in E. coli strains associated with colibacillosis in chickens.

    Methods: Fifty-two stock cultures of E. coli strains isolated from chickens diagnosed of colibacillosis were tested for their ability to produce haemolysis on blood agar and take up Congo red dye. Molecular characterization was carried out by polymerase chain reaction (PCR) amplification of virulence encoding genes associated with APEC.

    Results: Eleven (22%) and 41 (71%) were positive for haemolysis on 5% sheep red blood agar and Congo red agar, respectively. Nine virulence-associated genes were detected as follows: FimH (96%), csgA (52%), iss (48%), iut (33%), tsh (21%), cva (15%), kpsII (10%), pap (2%), and felA (2%).

    Conclusion: The APEC strains exhibited virulence properties and harbored virulence encoding genes which could be a threat to the poultry population and public health. The putative virulence genes were diverse and different in almost all isolate implying that pathogenesis was multi-factorial and the infection was multi-faceted which could be a source of concern in the detection and control of APEC infections.

    Matched MeSH terms: Escherichia coli Infections
  12. Hemasri S, Okene IA, Goni MD
    J Adv Vet Anim Res, 2018 Dec;5(4):490-495.
    PMID: 31453163 DOI: 10.5455/javar.2018.e304
    Objective: The main aim of this case report is to present a case of feline hemotropic mycoplasmosis that occurred concurrently with bacterial cystitis following the bite.

    Material and methods: A 3-year-old intact male domestic shorthair cat weighing 3.7 kg was referred to the Universiti Malaysia Kelantan Veterinary Clinic with clinical signs of hematuria and dysuria. History revealed that it was managed outdoor, fed with kibbles and wet food, but with no vaccination and deworming. Upon physical examination, the cat had a dull appearance, pale mucous membrane, normal respiratory rate, hypothermia, and bradycardia. Upon the examination of the urogenital system, there were urine burns at the anal region, necrotized penile tip, and presence of bite wound observed at the perineal region. Turgid and enlarged urinary bladder was identified upon palpation.

    Results: Diagnostic investigation revealed the hemotropic mycoplasmosis via microscopy, while urine culture was positive for Escherichia coli infection. The cat was successfully treated symptomatically.

    Conclusion: However, the prognosis of this cat was guarded given that the anemia was unresolved at the point of discharge.

    Matched MeSH terms: Escherichia coli Infections
  13. Palasubramaniam S, Muniandy S, Navaratnam P
    J Microbiol Immunol Infect, 2009 Apr;42(2):129-33.
    PMID: 19597644
    In addition to beta-lactamase production, loss of porins confers resistance to extended-spectrum beta-lactams in Klebsiella pneumoniae and Escherichia coli infection. This study describes the detection of SHV-12 extended-spectrum beta-lactamase (ESBL) subtype and the loss of OmpK35 porin in 4 strains of K. pneumoniae and E. coli.
    Matched MeSH terms: Escherichia coli Infections/microbiology
  14. Lam JC, Chai JY, Wong YL, Tan NW, Ha CT, Chan MY, et al.
    Ann Acad Med Singap, 2015 Nov;44(11):530-4.
    PMID: 27089960
    INTRODUCTION: Treatment of acute lymphoblastic leukaemia (ALL) using intensive chemotherapy has resulted in high cure rates but also substantial morbidity. Infective complications represent a significant proportion of treatment-related toxicity. The objective of this study was to describe the microbiological aetiology and clinical outcome of episodes of chemotherapy-induced febrile neutropaenia in a cohort of children treated for ALL at our institution.

    MATERIALS AND METHODS: Patients with ALL were treated with either the HKSGALL93 or the Malaysia-Singapore (Ma-Spore) 2003 chemotherapy protocols. The records of 197 patients who completed the intensive phase of treatment, defined as the period of treatment from induction, central nervous system (CNS)-directed therapy to reinduction from June 2000 to January 2010 were retrospectively reviewed.

    RESULTS: There were a total of 587 episodes of febrile neutropaenia in 197 patients, translating to an overall rate of 2.98 episodes per patient. A causative pathogen was isolated in 22.7% of episodes. An equal proportion of Gram-positive bacteria (36.4%) and Gram-negative bacteria (36.4%) were most frequently isolated followed by viral pathogens (17.4%), fungal pathogens (8.4%) and other bacteria (1.2%). Fungal organisms accounted for a higher proportion of clinically severe episodes of febrile neutropaenia requiring admission to the high-dependency or intensive care unit (23.1%). The overall mortality rate from all episodes was 1.5%.

    CONCLUSION: Febrile neutropaenia continues to be of concern in ALL patients undergoing intensive chemotherapy. The majority of episodes will not have an identifiable causative organism. Gram-positive bacteria and Gram-negative bacteria were the most common causative pathogens identified. With appropriate antimicrobial therapy and supportive management, the overall risk of mortality from febrile neutropaenia is extremely low.

    Matched MeSH terms: Escherichia coli Infections/epidemiology
  15. Kumar S, Narasimhan B, Lim SM, Ramasamy K, Mani V, Shah SAA
    Mini Rev Med Chem, 2019;19(7):609-621.
    PMID: 30526456 DOI: 10.2174/1389557519666181210162413
    BACKGROUND: A series of 6, 6'-(1,4-phenylene)bis(4-(4-bromophenyl)pyrimidin-2-amine) derivatives has been synthesized by Claisen-Schmidt condensation and its chemical structures was confirmed by FT-IR, 1H/13C-NMR spectral and elemental analyses. The molecular docking study was carried out to find the interaction between active bis-pyrimidine compounds with CDK-8 protein. The in vitro antimicrobial potential of the synthesized compounds was determined against Gram-positive and Gram-negative bacterial species as well fungal species by tube dilution technique. Antimicrobial results indicated that compound 11y was found to be most potent one against E. coli (MICec = 0.67 µmol/mL) and C. albicans (MICca = 0.17 µmol/mL) and its activity was comparable to norfloxacin (MIC = 0.47 µmol/mL) and fluconazole (MIC = 0.50 µmol/mL), respectively.

    CONCLUSION: Anticancer screening of the synthesized compounds using Sulforhodamine B (SRB) assay demonstrated that compounds 2y (IC50 = 0.01 µmol/mL) and 4y (IC50= 0.02 µmol/mL) have high antiproliferative potential against human colorectal carcinoma cancer cell line than the reference drug (5- fluorouracil) and these compounds also showed best dock score with better potency within the ATP binding pocket and may also be used lead for rational drug designing.

    Matched MeSH terms: Escherichia coli Infections/drug therapy
  16. Anwar A, Masri A, Rao K, Rajendran K, Khan NA, Shah MR, et al.
    Sci Rep, 2019 02 28;9(1):3122.
    PMID: 30816269 DOI: 10.1038/s41598-019-39528-0
    Herein, we report green synthesized nanoparticles based on stabilization by plant gums, loaded with citrus fruits flavonoids Hesperidin (HDN) and Naringin (NRG) as novel antimicrobial agents against brain-eating amoebae and multi-drug resistant bacteria. Nanoparticles were thoroughly characterized by using zetasizer, zeta potential, atomic force microscopy, ultravoilet-visible and Fourier transform-infrared spectroscopic techniques. The size of these spherical nanoparticles was found to be in the range of 100-225 nm. The antiamoebic effects of these green synthesized Silver and Gold nanoparticles loaded with HDN and NRG were tested against Acanthamoeba castellanii and Naegleria fowleri, while antibacterial effects were evaluated against methicillin-resistant Staphylococcus aureus (MRSA) and neuropathogenic Escherichia coli K1. Amoebicidal assays revealed that HDN loaded Silver nanoparticles stabilized by gum acacia (GA-AgNPs-HDN) quantitatively abolished amoeba viability by 100%, while NRG loaded Gold nanoparticles stabilized by gum tragacanth (GT-AuNPs-NRG) significantly reduced the viability of A. castellanii and N. fowleri at 50 µg per mL. Furthermore, these nanoparticles inhibited the encystation and excystation by more than 85%, as well as GA-AgNPs-HDN only completely obliterated amoeba-mediated host cells cytopathogenicity. Whereas, GA-AgNPs-HDN exhibited significant bactericidal effects against MRSA and E. coli K1 and reduced bacterial-mediated host cells cytotoxicity. Notably, when tested against human cells, these nanoparticles showed minimal (23%) cytotoxicity at even higher concentration of 100 µg per mL as compared to 50 µg per mL used for antimicrobial assays. Hence, these novel nanoparticles formulations hold potential as therapeutic agents against infections caused by brain-eating amoebae, as well as multi-drug resistant bacteria, and recommend a step forward in drug development.
    Matched MeSH terms: Escherichia coli Infections/drug therapy
  17. Lim KT, Yasin R, Yeo CC, Puthucheary S, Thong KL
    J Biomed Biotechnol, 2009;2009:165637.
    PMID: 19672454 DOI: 10.1155/2009/165637
    The emergence of Escherichia coli that produce extended spectrum beta-lactamases (ESBLs) and are multidrug resistant (MDR) poses antibiotic management problems. Forty-seven E. coli isolates from various public hospitals in Malaysia were studied. All isolates were sensitive to imipenem whereas 36 were MDR (resistant to 2 or more classes of antibiotics). PCR detection using gene-specific primers showed that 87.5% of the ESBL-producing E. coli harbored the blaTEM gene. Other ESBL-encoding genes detected were blaOXA, blaSHV, and blaCTX-M. Integron-encoded integrases were detected in 55.3% of isolates, with class 1 integron-encoded intI1 integrase being the majority. Amplification and sequence analysis of the 5'CS region of the integrons showed known antibiotic resistance-encoding gene cassettes of various sizes that were inserted within the respective integrons. Conjugation and transformation experiments indicated that some of the antibiotic resistance genes were likely plasmid-encoded and transmissible. All 47 isolates were subtyped by PFGE and PCR-based fingerprinting using random amplified polymorphic DNA (RAPD), repetitive extragenic palindromes (REPs), and enterobacterial repetitive intergenic consensus (ERIC). These isolates were very diverse and heterogeneous. PFGE, ERIC, and REP-PCR methods were more discriminative than RAPD in subtyping the E. coli isolates.
    Matched MeSH terms: Escherichia coli Infections/microbiology*
  18. Mustafa M, Chan WM, Lee C, Harijanto E, Loo CM, Van Kinh N, et al.
    Int J Antimicrob Agents, 2014 Apr;43(4):353-60.
    PMID: 24636429 DOI: 10.1016/j.ijantimicag.2014.01.017
    Doripenem is approved in the Asia-Pacific (APAC) region for treating nosocomial pneumonia (NP) including ventilator-associated pneumonia (VAP), complicated intra-abdominal infections (cIAIs) and complicated urinary tract infections (cUTIs). Clinical usage of doripenem (500mg intravenously, infused over 1h or 4h every 8h for 5-14 days) in APAC was evaluated in a prospective, open-label, non-comparative, multicentre study of inpatients (≥18 years) with NP, VAP, cIAI or cUTI. A total of 216 [intention-to-treat (ITT)] patients received doripenem: 53 NP (24.5%); 77 VAP (35.6%); 67 cIAI (31.0%); and 19 cUTI (8.8%). Doripenem MIC90 values for Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli and Klebsiella pneumoniae were 32, 32, 0.094 and 0.64μg/mL, respectively. Doripenem was used most commonly as monotherapy (86.6%) and as second-line therapy (62.0%). The clinical cure rate in clinically evaluable patients was 86.7% at the end of therapy (EOT) and 87.1% at test of cure (TOC) (7-14 days after EOT). In the ITT population, overall clinical cure rates were 66.2% at EOT and 56.5% at TOC. The median duration of hospital stay, intensive care unit (ICU) stay and mechanical ventilation was 20, 12 and 10 days, respectively. Of 146 discharged patients, 7 were re-admitted within 28 days of EOT; 1 VAP patient was re-admitted to the ICU. The all-cause mortality rate was 22.7% (49/216). The most common treatment-related adverse events were diarrhoea (1.4%) and vomiting (1.4%). Doripenem is a viable option for treating APAC patients with NP, VAP, cIAI or cUTI. [ClinicalTrials.gov: NCT 00986102].
    Matched MeSH terms: Escherichia coli Infections/drug therapy
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