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- Escherichia coli is a Gram-negative, usually motile, nonspore forming, facultative anaerobic bacillus. Most strains ferment lactose and thus appear as pink colonies when growing on selective media such as MacConkey agar, although up to 10% may not ferment lactose or may be slow lactose fermenters.
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Jan 1, 2008 · E. coli is Gram-negative and its envelope has three layers: cytoplasmic membrane, peptidoglycan, and outer membrane. The peptidoglycan is rigid determining the rod shape. To a good approximation, the E. coli cell has hemispherical caps and a cylindrical section in between.
- Galina Reshes, Sharon Vanounou, Itzhak Fishov, Mario Feingold
- 10.1529/biophysj.107.104398
- 2008
- Biophys J. 2008 Jan 1; 94(1): 251-264.
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Morphology and Staining of Escherichia Coli: E. coli is Gram-negative straight rod, 1-3 µ x 0.4-0.7 µ, arranged singly or in pairs (Fig. 28.1). It is motile by peritrichous flagellae, though some strains are non-motile. Spores are not formed.
Escherichia coli is a Gram-negative, facultatively anaerobic, chemo-organotrophic, non–spore-forming, rod-shaped bacterium and is a member of the family Enterobacteriaceae. E. coli is a commensal organism making up part of the normal flora of the human and animal intestinal tracts.
- Habitat of E. Coli
- Morphology of E. Coli
- Cultural Characteristics of E. Coli
- Pathogenicity of E. Coli
- Clinical Feature of E. Coli
- Clinical Manifestations of E. Coli
- Laboratory Diagnosis of E. Coli
- Treatment of E. Coli Infections
- Prevention and Control of E. Coli Infections
- References and Sources
E. coliwas discovered by Theodor Escherich in 1885 after isolating it from the feces of newborns.E. coliis the normal flora of the human body.The niche of E. colidepends upon the availability of the nutrients within the intestine of host organisms.The primary habitat of E. coliis in the gastrointestinal (GI) tract of humans and many other warm-blooded animals.E. coliis gram-negative (-ve) rod-shaped bacteria.It is 1-3 x 0.4-0.7 µm in size and 0.6 to 0.7 µm in volume.It is arranged singly or in pairs.It is motile due to peritrichous flagella.1. E. coli is a facultative anaerobe. 2. Its optimum growth temperature is 37°C and ranges from 10°C to 40°C.
E. coli is the most common and important member of the genus Escherichia.It is a Gram-negative, facultatively anaerobic, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms (endotherms).Human Escherichia coli strains are classified as commensal microbiota E. coli, enterovirulent E. coli, and extraintestinal pathogenic E. colion the basis of their genetic features and clinical outc...Most infections (with the exception of neonatal meningitis and gastroenteritis) are endogenous; that is, the E. colithat are part of the patient’s normal microbial flora are able to establish infec...Gastroenteritis
1. ETEC causes traveler’s diarrhea or infant diarrhea in infants. Pathogenesis involves plasmid-mediated, heat-stable (ST) and heat-labile (LT) enterotoxins that stimulate hypersecretion of fluids and electrolytes. 2. EPEC causes infant diarrhea in developing countries. Pathogenesis involves plasmid-mediated A/E histopathology, with disruption of normal microvillus structure resulting in malabsorption and diarrhea. 3. EAEC causes infant diarrhea in developing and probably developed countries...
1. Most gram-negative rods that produce UTIs originate in the colon, contaminate the urethra, ascend into the bladder, and may migrate to the kidney or prostate. 2. Although most strains of E. colican produce UTIs, the disease is more common with certain specific serogroups. 3. These bacteria are particularly virulent because of their ability to produce adhesins (primarily P pili, AAF/I, AAF/III, and Dr) that bind to cells lining the bladder and upper urinary tract (preventing the elimination...
Sepsis
1. When normal host defenses are inadequate, E colimay reach the bloodstream and cause sepsis. 2. Newborns may be highly susceptible to E colisepsis because they lack IgM antibodies. 3. Sepsis may occur secondary to urinary tract infection.
Gastroenteritis 1. watery or bloody diarrhea 2. vomiting 3. cramps 4. nausea 5. low-grade fever 6. dehydration 7. abdominal cramps Urinary tract infection The most common bacteria found to cause UTIs is Escherichia coli (E. coli). Other bacteria can cause UTI, but E. coliis the culprit about 90 percent of the time. The major manifestations of the i...
1. Most urine specimens are obtained from adult patients via the clean-catch midstream technique. 2. Bacteriuria can be detected microscopically using Gram staining of uncentrifuged urine specimens, Gram staining of centrifuged specimens, or direct observation of bacteria in urine specimens. 3. On staining, E coliappear as non-spore-forming, Gram-negative rod-shaped bacterium 4. Routine urine cultures should be plated using calibrated loops for the semi-quantitative method. Note: The most com...
Test/ Reactions
E. coli typically produces positive test results for indole, lysine decarboxylase, lactose, and mannitol fermentation and produces gas from glucose. An isolate from urine can be quickly identified as E. coli by its hemolysis on blood agar, typical colonial morphology with an iridescent “sheen” on differential media such as EMB agar, and a positive spot indole test result. More than 90% of E. coliisolates are positive for β-glucuronidase using the substrate 4-methylumbelliferyl-β-glucuronide (...
Gastroenteritis
1. ETEC: commercial immunoassays available for detecting ST in clinical specimens and cultures; PCR assays used with clinical specimens. 2. EPEC: Characteristic adherence to HEp-2 or HeLa cells; probes and amplification assays developed for the plasmid-encoded bundle-forming pili and gene targets on the “locus of enterocyte effacement” pathogenicity island. 3. EAEC: Characteristic adherence to HEp-2 cells; DNA probe and amplification assays developed for conserved plasmid. 4. STEC: Screen for...
The sulfonamides, ampicillin, cephalosporins, fluoroquinolones, and aminoglycosides have marked antibacterial effects against the enterics, but variation in susceptibility is great, and laboratory...E. coli meningitis requires antibiotics, such as third-generation cephalosporins (eg, ceftriaxone).E. colipneumonia requires respiratory support, adequate oxygenation, and antibiotics, such as third-generation cephalosporins or fluoroquinolones.In most cases of diarrheal disease, antibiotics are not prescribed. The best way to treat E coli infection is to drink plenty of fluids to avoid dehydration and to get as much rest as possible. How...It is widely recommended that caution be observed in regard to food and drink in areas where environmental sanitation is poor and that early and brief treatment (eg, with ciprofloxacin or trimethop...Their control depends on handwashing, rigorous asepsis, sterilization of equipment, disinfection, restraint in intravenous therapy, and strict precautions in keeping the urinary tract sterile (ie,...Ananthanarayan and Paniker. Textbook of Microbiology.Bailey and Scott’s Diagnostic Microbiology. Part 3. Section 7. Chapter 22. Enterobacteriaceae, 323.Mackie and McCartney Practical Medical Microbiology. Section B. Bacteria and Related Organisms. Chapter 20. Escherichia, 361.Murray, P. R., Rosenthal, K. S., & Pfaller, M. A. (2013). Medical microbiology. Philadelphia: Elsevier/SaundersNov 11, 2022 · E. coli in the colon synthesizes K and B complex vitamins and protects the GI tract against colonization with pathogenic microbes, while the host offers an ecological niche and nutrients. E. coli is the most common type of facultative anaerobes in the intestine, accounting for around 0.1% of the gut microbiota .
Escherichia coli (/ ˌɛʃəˈrɪkiə ˈkoʊlaɪ / ESH-ə-RIK-ee-ə KOH-lye) [1][2] is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus Escherichia that is commonly found in the lower intestine of warm-blooded organisms. [3][4] Most E. coli strains are harmless, but some serotypes such as EPEC, and ETEC are pathogenic and ...
Dec 31, 2022 · Escherichia coli have served as important model organisms for over a century—used to elucidate key aspects of genetics, evolution, molecular biology, and pathogenesis. However, defining which strains actually belong to this species is erratic and unstable due to shifts in the characters and criteria used to distinguish bacterial species.
![Schematic of Escherichia coli structure[3]. | Download Scientific Diagram](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 "Schematic of Escherichia coli structure[3]. | Download Scientific Diagram")
