close
This essay has been submitted by a student. This is not an example of the work written by professional essay writers.

Health Review: Mutational Changes

  • Subject: Science
  • Category: Genetics
  • Topic: DNA
  • Pages 2
  • Words: 804
  • Published: 17 December 2018
  • Downloads: 16
downloadDownload printPrint

Pssst… we can write an original essay just for you.

Any subject. Any type of essay. We’ll even meet a 3-hour deadline.

Get your price

121 writers online

blank-ico
Download PDF

The well-defined group is L. acidophilus dividing in Lactobacillus phylogenetic subgroups. Its meaning although is moderately built by DNA-DNA homology, 32% to 50% constituent content existing in genomic (GC) species (Felis & Dellaglio., 2007). In between ephemeral and permanent resident of normal gut flora Lactobacillus acts as a reservoir of antibiotic resistance genes and offers a model place for parallel gene transfer (Devirgiliis et al., 2011). E. coli having capability to colonize different anatomical sites in part to genome plasticity and transformation by gaining or loss of genetic material from which it got resistance or virulence influences. Therefore, horizontal transfer remains an important factor in adaptation and in the evolution of E. coli to different niches (Ahmed et al., 2008; Mellata et al., 2010).

UPEC strains can trigger acute infections and recurrent infections that do not respond to common antimicrobial treatments. ß[n1] [n2] -lactam antibiotics, fluoroquinolones, or trimethoprim/sulfamethoxazole are generally including in UTI treatment (Chulain et al., 2005; Johnson et al., 2004; Molina-López et al., 2011). According to Johnson (2000) treatment depend on patient age, sex, Pathogen involvement, course of disease, and the urinary tract anatomic areas. Resistance influence may be associated with variations in the bacterial genome by acquisition or by mutation or by horizontal transmission of an extra chromosomal or chromosomal material (Moura et al., 2009; Backer et al., 2008; Hong et al., 2009).

Randomly antibiotic resistance occur that relates to Some mutations. They are the significance of faults during DNA duplication or disorganization in repair mechanisms of DNA impairment in bacterial cell division and are recognized as natural mutations. Few changes at seven positions of the gyrA gene and in three positions of the parC gene Escherichia coli quinolone resistant phenotype is as a result of it. Mechanisms of antibiotic resistance involving efflux or import systems are genetically determined by mutations in regulatory regions of genes and even in promoter regions known as multidrug resistance (MDR) efflux pumps (Piddock., 2006; Depardieu et al, 2007).

Certain changes occur in non-dividing cells or in cells that have a low rate of division and are related with the nonlethal selection pressure that favors bacterial cells. Such mutations are named adaptive and represent the main source of emergence of antibiotic-resistant phenotypes in natural conditions. DNA polymerase V prone-errors (umuCD) and DNA polymerase IV (dinB) which increase transitory the rate of mutations are the main points in these processes. Enhancing the rate of occurrence of antibiotic-resistant phenotypes of Escherichia coli some antibiotics are capable to produce bacterial DNA damage and trigger the mutagenic SOS response. Accumulation of single-stranded DNA because of lesions that blocks replication of the bacterial chromosome leads to the formation of RecA nucleoprotein complexes. A required step for assembling mutagen- dependent DNA polymerase V UmuD’2C is another role of coprotease RecA is to Process UmuD to UmuD’. It allowed DNA replication to remain in this way, the cost being the loss of dependability and the entrance of mutations (Rosche & Foster., 2000; Sutton et al., 2000, Bjedov et al., 2003; Janion. 2008)

Escherichia coli cells, known as MarA, Sox and Rob, which activate a set of 40 supporters belonging to marA / soxS / rob regulon, are some transcription factors whose function includes antibiotic resistance. Multiple antibiotic resistance is inherently determined by locus mar, placed at 34 minutes on the chromosome of Escherichia coli, by monitoring the intrinsic exposure of this bacterial strains. Four genes marC, marR, marA and marB present in MarCRAB locus are arranged in two transcriptional units. Escherichia coli response to oxidative stress and to action of weak acids. In fact, the first organizer initiated by MarA is even marRAB promoter, which has the effect of increasing their own synthesis. MarR inactivation by mutations or small molecules, activates marRAB transcription and determines antibiotic resistance phenotype duration (Barbosa et al.,2000; Alekshun et al.,2004).

Mutational changes in the FQ target enzymes, namely, DNA topoisomerase II (DNA gyrase) and topoisomerase IV, are recognized to be the major mechanisms through which resistance develops in Escherichia coli. The quinolone resistance-determining regions (QRDRs in FQ-resistant isolates, mutational hot spots are localized in defined regions. the primary target in Gram-negative bacteria, in isolates displaying FQ resistance, DNA gyrase, commonly presents substitutions at amino acid position Ser83 and/or Asp87 of the GyrA subunit, whereas substitutions at residues Ser80 and Glu84 are commonly identified alterations in the ParC subunit of the topoisomerase IV (Heisig., 1996; Ozeki et al., 1997). According to Hopkins et al., (2005) and Strahilevitz et al., (2009), mutations in the quinolone target genes are required to achieve a clinical level of resistance, some other mechanisms may also contribute to quinolone/FQ resistance, including decreased uptake of the drug due to the loss of a membrane- bound porin; drug extrusion via efflux pumps, some of which may have a broad substrate specificity; or one of the further described plasmid-mediated quinolone resistance (PMQR) mechanisms.

Remember: This is just a sample from a fellow student.

Your time is important. Let us write you an essay from scratch

experts 450+ experts on 30 subjects ready to help you just now

delivery Starting from 3 hours delivery

Find Free Essays

We provide you with original essay samples, perfect formatting and styling

Cite this Essay

To export a reference to this article please select a referencing style below:

Health review: mutational changes. (2018, December 17). GradesFixer. Retrieved January 29, 2022, from https://gradesfixer.com/free-essay-examples/health-review-mutational-changes/
“Health review: mutational changes.” GradesFixer, 17 Dec. 2018, gradesfixer.com/free-essay-examples/health-review-mutational-changes/
Health review: mutational changes. [online]. Available at: <https://gradesfixer.com/free-essay-examples/health-review-mutational-changes/> [Accessed 29 Jan. 2022].
Health review: mutational changes [Internet]. GradesFixer. 2018 Dec 17 [cited 2022 Jan 29]. Available from: https://gradesfixer.com/free-essay-examples/health-review-mutational-changes/
copy to clipboard
close

Sorry, copying is not allowed on our website. If you’d like this or any other sample, we’ll happily email it to you.

    By clicking “Send”, you agree to our Terms of service and Privacy statement. We will occasionally send you account related emails.

    close

    Attention! This essay is not unique. You can get a 100% Plagiarism-FREE one in 30 sec

    Receive a 100% plagiarism-free essay on your email just for $4.99
    get unique paper
    *Public papers are open and may contain not unique content
    download public sample
    close

    Sorry, we could not paraphrase this essay. Our professional writers can rewrite it and get you a unique paper.

    close

    Thanks!

    Please check your inbox.

    Want us to write one just for you? We can custom edit this essay into an original, 100% plagiarism free essay.

    thanks-icon Order now
    boy

    Hi there!

    Are you interested in getting a customized paper?

    Check it out!
    Having trouble finding the perfect essay? We’ve got you covered. Hire a writer
    exit-popup-close

    Haven't found the right essay?

    Get an expert to write you the one you need!

    exit-popup-print

    Professional writers and researchers

    exit-popup-quotes

    Sources and citation are provided

    exit-popup-clock

    3 hour delivery

    exit-popup-persone