Pathogen Escherichia coli Article 2022

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TITLE
NAME
CHAMBERLAIN UNIVERSITY
DATE

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Abstract
The article is proposed to provide a brief insight about the pathogen Escherichia coli, its
classification and morphological characters, along with the suitable growth conditions and
nutritional needs. It also discusses about the pathogenicity of the bacteria, along with the
virulence factors and the type of disease it produces within the host. The symptoms, diagnosis
and therapeutic intervention for the treatment of the disease is also explained in details.
Article Summary
E.coli is a gram-negative pathogenic bacteria which is found in the human intestine. The toxic
and pathogenic strains of E,coli causes severe gastrointestinal problems such as diarrhea and
urinary tract infection. It is a mesophile and can grow at moderate temperatures. It is a
facultative anaerobe and can grow in absence of oxygen. It causes gastrointestinal problems in
human as well as urinary tract infection. It is sensitive to quinolones and aminoglycosides,
however some strains of E.coli exhibit multi drug resistance.
Pathogen Information
Classification of microorganism
Escherichia Coli is an unicellular, prokaryotic bacteria since it does not have a nucleus with a
distinct nuclear membrane, nor does it have any specialized cellular organelles, instead it has a
genetic material called “nucleoid”. It belongs to the genus “Escherichia” and family of
“Enterobacteriaceae”. It is a gram negative, rod shaped bacteria. It does not produce spores,
thus it is a non-spore forming microorganism, some of them contains peritrichous flagella for
mobility while the others are non-motile, presence of fimbriae is also common in some strains.
Few strains of E.coli consist of polysaccharide capsule, which increases its pathogenicity and
also protects the bacteria from getting engulfed by macrophages, thus preventing phagocytosis.
They are facultative anaerobes, which means that they are able to produce in presence or
absence of oxygen through aerobic or anaerobic respiration respectively.

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Cellular/ structural (in case of viruses) characteristics.
Escherichia coli is a gram-negative rod shaped prokaryotic bacteria. The gram staining is a type
of differential staining which helps in the differentiation between a gram-negative bacteria and
gram negative. On gram staining, it takes up the gram-negative stain (saffranin) and appears
reddish pink. Since it is a gram-negative rod, it has a very thin peptidoglycan layer. It mainly
contains an outer layer consisting of phospholipids and polysaccharides, which gives a overall
negative charge to the bacteria. As a result, it does not retain the Gram-positive crystal violet
strain.
Susceptibility to antibiotics/ antiviral or antifungals
E.coli is found to be sensitive against antibiotics such as norfloxacin, ciprofloxacin, gentamicin
and chloramphenicol. Ciprofloxacin and norfloxacin belongs to the class of Quinolone
antibiotics, whereas, gentamicin belongs to the class of aminoglycoside antibiotics. The
quinolones restricts bacterial growth by inhibiting replication of bacterial DNA by preventing the
unwinding of the DNA through disruption of the action of DNA gyrase or Topoisomerase which
induces a negative supercoiling of the DNA and thus relaxes the DNA. It is bactericidal in
nature. The aminoglycosides are protein synthesis inhibitor which disrupts the synthesis of
protein of the bacteria by binding to the 30S ribosomal subunit, inhibiting the translocation of
peptidyl tRNA from the A-site to the P-site of the ribosomal subunit, thus leading to misreading
of the genetic code. However, it is found that E.coli is getting resistant to antibiotics by
producing extended spectrum beta lactamase, which is an enzyme responsible for antibiotic
ineffectivity and helping the bacteria to exhibit multi drug resistance.
Growth conditions
E.coli is a mesophile, which grows best around 20-370Celsius. It grows in a neutral pH
environment. E.coli is also known as gut bacteria, as it resides inside the gut of the human
body, where the temperature is around 370Celsius. It is a facultative anaerobe and is able to