Call us toll-free

Quick academic help

Don't let the stress of school get you down! Have your essay written by a professional writer before the deadline arrives.

Calculate the price


275 Words


Search Result - International Journal of Advanced …

(2015)Antibiotic consumption and molecular epidemiology of ESBL-producing escherichia coli and klebsiella pneumoniae in a Lebanese hospital Doctoral thesis, University of Surrey.

pneumoniae positive for ESBL phenotype were examined for the presence of TEM, SHV and CTX-M genes.

Escherichia coli is an important nosocomial pathogen and extended-spectrum cephalosporin (ESC) resistance E. coli is recognized as the global drug-resistant threat. This study aims to determine the resistance mechanisms of ESC and genetic diversity of Malaysian E. coli strains using various phenotypic and genotypic approaches. One hundred ten non-repeat E. coli strains were isolated from the stools of paediatric patients in 2009 from a tertiary hospital in Malaysia. Twenty-one were categorized as extended spectrum beta-lactamase (ESBL)-producers using the double-disk synergy test and ESBL E-test. CTX-M-15 was the pre-dominant CTX-M variant (77%). Class 1 integron was the most common class of integrons found in the E. coli strains (76%); however, they lack gene cassette encoding ESBL genes. Using PFGE, three strains displayed DNA degradation (Dnd) phenotype and few CTX-M-15-positive strains with indistinguishable pulsotypes were identified. To better understand the dissemination of CTX-M genes, E. coli strains from clinical, zoonotic, food and environment samples isolated between 2002 - 2011 in Malaysia were screened for ESBL-production. Using multi-locus sequence typing (MLST), 6 out of 35 CTX-M positive E. coli strains belonged to the sequence type (ST) ST131, an E. coli clone notorious for the global dissemination of CTX-M genes. Insertional sequences IS26 and ISEcp1 were the most common genetic environments for CTX-M genes in the Malaysian E. coli strains. The degradation phenotype which was observed earlier in this thesis was overcome for 12 Dnd+ E. coli strains by adding thiourea into the PFGE run. The dnd operon, responsible for the phosphorothioation modification of DNA, was detected in all Dnd+ E. coli strains by PCR. Further genomic analysis of the genetic environment of dnd operons of 52 global E. coli genomes revealed a total of 7 types of dnd-encoding genomic islands, indicating substantial diversity in these regions. dnd operons were more often found in pathogenic E. coli, indicating a possible linkage of the dnd operons with E. coli pathogenicity. Two highly related E. coli strains EC302/04 and EC096/10 with single band difference in their pulsotypes (identified in the first part of this study) were investigated using whole genome sequencing (WGS). EC302/04 and EC096/10 that were isolated from tracheal aspirate and a stool specimen, respectively, shared the same sequence type ST349, and serotype O166:H5. EC302/04 harboured a 140,232 bp IncFII plasmid, pEC302/04, that was absent in EC096/10. Plasmid pEC302/04 is self-transferable and carried resistance genes (blaTEM-1; integron-encoded- sul1, cml, and aadA) and two iron-acquisition systems. Phylogenomic analysis with 38 global E. coli of various pathotypes revealed that ExPEC and intestinal strains may share similar phylogenetic signals. This may help in identifying commensal-like strains with extraintestinal virulence potential. Phylogenomic analysis also unveiled ExPEC with rare genotypes, indicating the importance of genomic approach in detecting the potential emergence of new ExPEC lineage(s). Besides providing comprehensive understanding on the resistance mechanisms of the clinically important CTX-M genes, this thesis also demonstrates the usefulness of whole genome sequence approach in investigating the resistance mechanisms and genetic diversity of specific region or whole genome of various types of E. coli strains. (500 words)

The Times & The Sunday Times

Screening and confirmation of ESBL-producing phenotypes among the clinical isolates were performed according to the guidelines of the Clinical and Laboratory Standard Institute (CLSI, 2012).

News and opinion from The Times & The Sunday Times

Order now

    As soon as we have completed your work, it will be proofread and given a thorough scan for plagiarism.


    Our clients' personal information is kept confidential, so rest assured that no one will find out about our cooperation.


    We write everything from scratch. You'll be sure to receive a plagiarism-free paper every time you place an order.


    We will complete your paper on time, giving you total peace of mind with every assignment you entrust us with.


    Want something changed in your paper? Request as many revisions as you want until you're completely satisfied with the outcome.

  • 24/7 SUPPORT

    We're always here to help you solve any possible issue. Feel free to give us a call or write a message in chat.

Order now
  • You submit your order instructions

  • We assign an appropriate expert

  • The expert takes care of your task

  • We send it to you upon completion

Order now
  • 37 684

    Delivered orders

  • 763

    Professional writers

  • 311

    Writers online

  • 4.8/5

    Average quality score

Order now
  • Kim

    "I have always been impressed by the quick turnaround and your thoroughness. Easily the most professional essay writing service on the web."

  • Paul

    "Your assistance and the first class service is much appreciated. My essay reads so well and without your help I'm sure I would have been marked down again on grammar and syntax."

  • Ellen

    "Thanks again for your excellent work with my assignments. No doubts you're true experts at what you do and very approachable."

  • Joyce

    "Very professional, cheap and friendly service. Thanks for writing two important essays for me, I wouldn't have written it myself because of the tight deadline."

  • Albert

    "Thanks for your cautious eye, attention to detail and overall superb service. Thanks to you, now I am confident that I can submit my term paper on time."

  • Mary

    "Thank you for the GREAT work you have done. Just wanted to tell that I'm very happy with my essay and will get back with more assignments soon."

Ready to tackle your homework?

Place an order