Pathogenic Escherichia coli

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(Redirected from
Enteropathogenic E. coli
)
For Escherichia coli in general, see
Escherichia coli (molecular biology)
.

Pathogenic Escherichia coli
Scientific classification
Domain:
Bacteria
Phylum:
Pseudomonadota
Class:
Gammaproteobacteria
Order:
Enterobacteriales
Family:
Enterobacteriaceae
Genus:
Escherichia
Species:
E. coli
Binomial name
Escherichia coli
(Migula 1895)
Castellani and Chalmers 1919
Synonyms

Bacillus coli communis Escherich 1885

Escherichia coli (

virulence genes carried only by the pathogens.[3]

Introduction

E. coli and related bacteria constitute about 0.1% of

host organism for the majority of work with recombinant DNA
.

German paediatrician and bacteriologist Theodor Escherich discovered E. coli in 1885,[5] and it is now classified as part of the Gammaproteobacterial family Enterobacteriaceae.[7]

Serotypes

Structure of a lipopolysaccharide

Pathogenic E. coli strains can be categorized based on elements that can elicit an immune response in animals, namely:[citation needed]

  1. O antigen: part of lipopolysaccharide layer
  2. K antigen: capsule
  3. H antigen: flagellin

For example, E. coli strain EDL933 is of the

O157:H7
group.

O antigen

Main article:
O antigen

The outer membrane of an E. coli cell contains millions of lipopolysaccharide (LPS) molecules, which consists of:[citation needed]

  1. O antigen, a polymer of immunogenic repeating oligosaccharides
    (1–40 units)
  2. Core region of phosphorylated nonrepeating oligosaccharides
  3. Lipid A (endotoxin)

The O antigen is used for serotyping E. coli and these O group designations go from O1 to O181, with the exception of some groups which have been historically removed, namely O31, O47, O67, O72, O93 (now K84), O94, and O122; groups 174 to 181 are provisional (O174=OX3 and O175=OX7) or are under investigation (176 to 181 are STEC/VTEC).[8] Additionally subtypes exist for many O groups (e.g. O128ab and O128ac).[8] Antibodies towards several O antigens cross-react with other O antigens and partially to K antigens not only from E. coli, but also from other Escherichia species and Enterobacteriaceae species.[8]

The O antigen is encoded by the rfb gene cluster. rol (cld) gene encodes the regulator of lipopolysaccharide O-chain length.[citation needed]

K antigen

See also: Polysaccharide § Bacterial capsular polysaccharides

The acidic capsular polysaccharide (CPS) is a thick, mucous-like, layer of polysaccharide that surrounds some pathogen E. coli.[citation needed]

There are two separate groups of K-antigen groups, named group I and group II (while a small in-between subset (K3, K10, and K54/K96) has been classified as group III).[8] The former (I) consist of 100 kDa (large) capsular polysaccharides, while the latter (II), associated with extraintestinal diseases, are under 50 kDa in size.[8]

Group I K antigens are only found with certain O-antigens (O8, O9, O20, and O101 groups), they are further subdivided on the basis of absence (IA, similar to that of Klebsiella species in structure) or presence (IB) of amino sugars and some group I K-antigens are attached to the lipid A-core of the lipopolysaccharide (KLPS), in a similar way to O antigens (and being structurally identical to O antigens in some instances are only considered as K antigens when co-expressed with another authentic O antigen).[8]

Group II K antigens closely resemble those in

gram-positive bacteria and greatly differ in composition and are further subdivided according to their acidic components, generally 20–50% of the CPS chains are bound to phospholipids.[8]

In total there are 60 different K antigens that have been recognized (K1, K2a/ac, K3, K4, K5, K6, K7 (=K56), K8, K9 (=O104), K10, K11, K12 (K82), K13(=K20 and =K23), K14, K15, K16, K18a, K18ab (=K22), K19, K24, K26, K27, K28, K29, K30, K31, K34, K37, K39, K40, K41, K42, K43, K44, K45, K46, K47, K49 (O46), K50, K51, K52, K53, K54 (=K96), K55, K74, K84, K85ab/ac (=O141), K87 (=O32), K92, K93, K95, K97, K98, K100, K101, K102, K103, KX104, KX105, and KX106).[citation needed]

H antigen

See also:
flagella

The H antigen is a major component of flagella, involved in E. coli movement. It is generally encoded by the fliC gene[citation needed]

There are 53 identified H antigens, numbered from H1 to H56 (H13 and H22 were not E. coli antigens but from Citrobacter freundii, and H50 was found to be the same as H10).[9]

Role in disease

In humans and in

domestic animals, virulent strains of E. coli can cause various diseases.[citation needed
]

In humans :

septicaemia and gram-negative pneumonia.[10]

Gastrointestinal infection

Low-temperature electron micrograph of a cluster of E. coli bacteria, magnified 10,000 times. Each individual bacterium is a rounded cylinder.

Certain strains of E. coli, such as

Food poisoning caused by E. coli can result from eating unwashed vegetables or poorly butchered and undercooked meat.[citation needed
]

O157:H7 is also notorious for causing serious and even life-threatening complications such as

2006 United States E. coli outbreak due to fresh spinach.[citation needed
]

The

2011 E. coli outbreak in Europe. Severity of the illness varies considerably; it can be fatal, particularly to young children, the elderly or the immunocompromised, but is more often mild.[citation needed
]

Earlier, poor hygienic methods of preparing meat in Scotland killed seven people in 1996 due to E. coli poisoning, and left hundreds more infected.[citation needed]

E. coli can harbour both

heat-labile enterotoxins. The latter, termed LT, contain one A subunit and five B subunits arranged into one holotoxin, and are highly similar in structure and function to cholera toxins. The B subunits assist in adherence and entry of the toxin into host intestinal cells, while the A subunit is cleaved and prevents cells from absorbing water, causing diarrhea. LT is secreted by the Type 2 secretion pathway.[11]

If E. coli bacteria escape the intestinal tract through a perforation (for example from an

antibiotics as streptomycin or gentamicin. Recent research suggests treatment of enteropathogenic E. coli with antibiotics may significantly increase the chance of developing haemolytic-uremic syndrome.[12]

Intestinal mucosa-associated E. coli are observed in increased numbers in the inflammatory bowel diseases, Crohn's disease and ulcerative colitis.[13] Invasive strains of E. coli exist in high numbers in the inflamed tissue, and the number of bacteria in the inflamed regions correlates to the severity of the bowel inflammation.[14]

Gastrointestinal infections can cause the body to develop memory T cells to attack gut microbes that are in the intestinal tract. Food poisoning can trigger an immune response to microbial gut bacteria. Some researchers suggest that it can lead to inflammatory bowel disease.[15]

Virulence properties

Enteric E. coli (EC) are classified on the basis of serological characteristics and virulence properties.[10] The major pathotypes of E. coli that cause diarrhea are listed below.[16]

Name Hosts Type of diarrhea Description
Enterotoxigenic
E. coli (ETEC) 		causative agent of diarrhea (without fever) in humans, pigs, sheep, goats, cattle, dogs, and horses Watery ETEC uses various colonization factors (CFs) to bind
enterotoxins
:

ETEC strains are noninvasive, and they do not leave the intestinal lumen. ETEC is the leading bacterial cause of diarrhea in children in the developing world, as well as the most common cause of

traveler's diarrhea. Each year, there are estimated to be 840 million cases of ETEC in developing countries. About 280 million of these cases, as well as 325,000 deaths, are in children under the age of five.[16]

Enteropathogenic E. coli (EPEC) causative agent of diarrhea in humans, rabbits, dogs, cats and horses Watery Like ETEC, EPEC also causes diarrhea, but the molecular mechanisms of colonization and aetiology are different. EPEC lack ST and LT toxins, but they use an adhesin known as intimin to bind host intestinal cells. This pathotype has an array of virulence factors that are similar to those found in Shigella. Adherence to the intestinal mucosa causes a rearrangement of actin in the host cell, causing significant deformation. EPEC cells are moderately invasive (i.e. they enter host cells) and elicit an inflammatory response. Changes in intestinal cell ultrastructure due to "attachment and effacement" is likely the prime cause of diarrhea in those afflicted with EPEC.
Enteroaggregative
E. coli (EAEC) 		found only in humans Watery So named because they have fimbriae which aggregate tissue culture cells, EAEC bind to the intestinal mucosa to cause watery diarrhea without fever. EAEC are noninvasive. They produce a hemolysin and an ST enterotoxin similar to that of ETEC.
Enteroinvasive
E. coli (EIEC) 		found only in humans Bloody or nonbloody EIEC infection causes a syndrome that is identical to shigellosis, with profuse diarrhea and high fever.
Enterohemorrhagic
E. coli
 (EHEC) 		found in humans, cattle, and goats Bloody or nonbloody The most infamous member of this pathotype is strain
hemolytic-uremic syndrome and sudden kidney failure. It uses bacterial fimbriae for attachment (E. coli common pilus, ECP),[17]
is moderately invasive and possesses a phage-encoded shiga toxin that can elicit an intense inflammatory response.
Adherent-Invasive E. coli (AIEC) found in humans - AIEC are able to invade intestinal epithelial cells and replicate intracellularly. It is likely that AIEC are able to proliferate more effectively in hosts with defective innate immunity. They are associated with the ileal mucosa in Crohn's disease.[18]

Epidemiology of gastrointestinal infection

Transmission of pathogenic E. coli often occurs via

cucumber,[27] raw ground beef,[28] raw seed sprouts or spinach,[22] raw milk, unpasteurized juice, unpasteurized cheese and foods contaminated by infected food workers via fecal–oral route.[20]

According to the

U.S. Food and Drug Administration, the fecal-oral cycle of transmission can be disrupted by cooking food properly, preventing cross-contamination, instituting barriers such as gloves for food workers, instituting health care policies so food industry employees seek treatment when they are ill, pasteurization of juice or dairy products and proper hand washing requirements.[20]

Shiga toxin-producing E. coli (STEC), specifically serotype O157:H7, have also been transmitted by flies,[29][30][31] as well as direct contact with farm animals,[32][33] petting zoo animals,[34] and airborne particles found in animal-rearing environments.[35]

Urinary tract infection

E. coli bacteria

Uropathogenic E. coli (UPEC) is responsible for approximately 90% of

kidneys (causing pyelonephritis),[36] or the prostate in males. Because women have a shorter urethra than men, they are 14 times more likely to suffer from an ascending UTI.[10]

Uropathogenic E. coli use

uroepithelial cells.[10] Approximately 1% of the human population lacks this receptor, [citation needed] and its presence or absence dictates an individual's susceptibility or non-susceptibility, respectively, to E. coli urinary tract infections. Uropathogenic E. coli produce alpha- and beta-hemolysins, which cause lysis of urinary tract cells.[citation needed
]

Another virulence factor commonly present in UPEC is the

PI-3 kinase.[37]

UPEC can evade the body's innate immune defences (e.g. the complement system) by invading superficial umbrella cells to form intracellular bacterial communities (IBCs).[38] They also have the ability to form K antigen, capsular polysaccharides that contribute to biofilm formation. Biofilm-producing E. coli are recalcitrant to immune factors and antibiotic therapy, and are often responsible for chronic urinary tract infections.[39] K antigen-producing E. coli infections are commonly found in the upper urinary tract.[10]

Descending infections, though relatively rare, occur when E. coli cells enter the upper urinary tract organs (

ureters) from the blood stream.[citation needed
]

Neonatal meningitis (NMEC)

It is produced by a serotype of Escherichia coli that contains a capsular antigen called K1. The colonization of the newborn's intestines with these strains, that are present in the mother's vagina, lead to bacteremia, which leads to

FcRn only mediates the transfer of IgG), plus the fact that the body recognizes as self the K1 antigen, as it resembles the cerebral glycopeptides, this leads to a severe meningitis in the neonates.[citation needed
]

Possible role in colorectal cancer

Some E. coli strains contain a polyketide synthase genomic island (pks), which encodes a multi-enzymatic machinery that produces colibactin, a substance that damages DNA. About 20% of humans are colonized with E. coli that harbor the pks island.[41] Colibactin can cause cellular senescence[42] or cancer by damaging DNA.[43] However, the mucosal barrier prevents E. coli from reaching the surface of enterocytes. Mucin production diminishes in the presence of inflammation.[44] Only when some inflammatory condition co-occurs with E. coli infection is the bacterium able to deliver colibactin to enterocytes and induce tumorogenesis.[45]

Animal diseases

In animals, virulent strains of E. coli are responsible of a variety of diseases, among others

dairy cows, colibacillosis also associated with chronic respiratory disease with Mycoplasma where it causes perihepatitis, pericarditis, septicaemic lungs, peritonitis etc. in poultry, and Alabama rot in dogs.[citation needed
]

Most of the serotypes isolated from poultry are pathogenic only for birds. So avian sources of E. coli do not seem to be important sources of infections in other animals.[46]

  • Colibacillosis in domestic chicken
    Colibacillosis in domestic chicken
  • Mastitis in cows
    Mastitis in cows

Laboratory diagnosis

Diagnosis of infectious diarrhea and identification of

stool culture with subsequent antibiotic sensitivity testing. It requires a minimum of 2 days and maximum of several weeks to culture gastrointestinal pathogens. The sensitivity (true positive) and specificity (true negative) rates for stool culture vary by pathogen, although a number of human pathogens can not be cultured. For culture-positive samples, antimicrobial resistance testing takes an additional 12–24 hours to perform.[citation needed
]

Current

molecular diagnostic tests can identify E. coli and antimicrobial resistance in the identified strains much faster than culture and sensitivity testing. Microarray-based platforms can identify specific pathogenic strains of E. coli and E. coli-specific AMR genes in two hours or less with high sensitivity and specificity, but the size of the test panel (i.e., total pathogens and antimicrobial resistance genes) is limited. Newer metagenomics-based infectious disease diagnostic platforms are currently being developed to overcome the various limitations of culture and all currently available molecular diagnostic technologies.[citation needed
]

In stool samples, microscopy will show

citrate-negative (no change-green colour). Tests for toxin production can use mammalian cells in tissue culture, which are rapidly killed by shiga toxin. Although sensitive and very specific, this method is slow and expensive.[47]

Typically, diagnosis has been done by culturing on sorbitol-MacConkey medium and then using typing antiserum. However, current latex assays and some typing antisera have shown cross reactions with non-E. coli O157 colonies. Furthermore, not all E. coli O157 strains associated with HUS are nonsorbitol fermentors.

The Council of State and Territorial Epidemiologists recommend that clinical laboratories screen at least all bloody stools for this pathogen. The U.S. Centers for Disease Control and Prevention recommend that "all stools submitted for routine testing from patients with acute community-acquired diarrhea (regardless of patient age, season of the year, or presence or absence of blood in the stool) be simultaneously cultured for E. coli O157:H7 (O157 STEC) and tested with an assay that detects Shiga toxins to detect non-O157 STEC".[48][49]

Antibiotic therapy and resistance

Main article:
Antibiotic resistance

Bacterial infections are usually treated with

trimethoprim-sulfamethoxazole, ciprofloxacin, nitrofurantoin and the aminoglycosides.[citation needed
]

overuse of antibiotics in humans, but some of it is probably due to the use of antibiotics as growth promoters in animal feeds.[50] A study published in the journal Science in August 2007 found the rate of adaptative mutations in E. coli is "on the order of 10−5 per genome per generation, which is 1,000 times as high as previous estimates," a finding which may have significance for the study and management of bacterial antibiotic resistance.[51]

Antibiotic-resistant E. coli may also pass on the genes responsible for antibiotic resistance to other species of bacteria, such as Staphylococcus aureus, through a process called horizontal gene transfer. E. coli bacteria often carry multiple drug resistance plasmids, and under stress, readily transfer those plasmids to other species. Mixing of species in the intestines allows E. coli to accept and transfer plasmids from and to other bacteria. Thus, E. coli and the other enterobacteria are important reservoirs of transferable antibiotic resistance.[52]

Beta-lactamase strains

Resistance to

NDM-1) that even gives resistance to intravenous antibiotic carbapenem, were discovered in India and Pakistan on E. coli bacteria.[citation needed
]

Increased concern about the prevalence of this form of "

superbug" in the United Kingdom has led to calls for further monitoring and a UK-wide strategy to deal with infections and the deaths.[54] Susceptibility testing should guide treatment in all infections in which the organism can be isolated for culture.[citation needed
]

Phage therapy

Phage therapy—viruses that specifically target pathogenic bacteria—has been developed over the last 80 years, primarily in the former Soviet Union, where it was used to prevent diarrhea caused by E. coli.[55] Presently, phage therapy for humans is available only at the Phage Therapy Center in the Republic of Georgia and in Poland.[56] However, on January 2, 2007, the United States FDA gave Omnilytics approval to apply its E. coli O157:H7 killing phage in a mist, spray or wash on live animals that will be slaughtered for human consumption.[57] The

enterobacteria phage T4, a highly studied phage, targets E. coli for infection.[citation needed
]

While phage therapy as a treatment for E. coli is unavailable in the US, some commercially available dietary supplements contain strains of phage that target E. coli and have been shown to reduce E. coli load in healthy subjects.[58] This is not considered phage therapy, however, because it does not involve selection of phages with activity against a patient's specific strain of bacterium.[citation needed]

Vaccination

Researchers have actively been working to develop safe, effective

phase III clinical trial to verify the large-scale efficacy of the treatment is planned.[60]

In 2006, Fort Dodge Animal Health (Wyeth) introduced an effective, live, attenuated vaccine to control airsacculitis and peritonitis in chickens. The vaccine is a genetically modified avirulent vaccine that has demonstrated protection against O78 and untypeable strains.[61]

In January 2007, the Canadian biopharmaceutical company Bioniche announced it has developed a cattle vaccine which reduces the number of O157:H7 shed in manure by a factor of 1000, to about 1000 pathogenic bacteria per gram of manure.[62][63][64]

In April 2009, a Michigan State University researcher announced he had developed a working vaccine for a strain of E. coli. Dr. Mahdi Saeed, Professor of epidemiology and infectious disease in MSU's colleges of Veterinary Medicine and Human Medicine, has applied for a patent for his discovery and has made contact with pharmaceutical companies for commercial production.[65]

In May 2018, a team led by researchers at Washington University School of Medicine collaborated with Johns Hopkins University to conduct a study which delves deeper into the known link between blood type and the severity of E. coli infection.[66] Results of the study showed that "the bacterium is more likely to cause severe diarrhea in people with type A blood," and this finding may aid current and future efforts to develop an effective vaccine against the pathogenic strains of E. coli.[66][67]

See also

References

  1. ^ "Escherichia coli O157:H7". CDC Division of Bacterial and Mycotic Diseases. Retrieved 2011-04-19.
  2. PMID 15842119
    .
  3. ^
    S2CID 3343088
    .
  4. PMID 15831718
    .
  5. ^ a b Feng P, Weagant S, Grant M (2002-09-01). "Enumeration of Escherichia coli and the Coliform Bacteria". Bacteriological Analytical Manual (8th ed.). FDA/Center for Food Safety & Applied Nutrition. Archived from the original on 2009-05-19. Retrieved 2007-01-25.
  6. ^ Thompson, Andrea (2007-06-04). "E. coli Thrives in Beach Sands". Live Science. Retrieved 2007-12-03.
  7. ^ "Escherichia". Taxonomy Browser. NCBI. Retrieved 2007-11-30.
  8. ^
    ISBN 978-0-387-24144-9
    . British Library no. GBA561951.
  9. ^ Wang L; Rothemund D; Reeves PR (May 2003). "Species-Wide Variation in the Escherichia coli Flagellin (H-Antigen) Gene". Journal of Bacteriology. 185 (9): 2396–2943.
    PMID 12700273
    .
  10. ^ a b c d e f Todar, K. "Pathogenic E. coli". Online Textbook of Bacteriology. University of Wisconsin–Madison Department of Bacteriology. Retrieved 2007-11-30.
  11. PMID 12011463
    .
  12. PMID 10874060
    .
  13. S2CID 9818154
    .
  14. PMID 18043660
    .
  15. PMID 22923434
    .
  16. ^
    PMID 24092857
    .
  17. PMID 17563352
    .
  18. PMID 25133024
    .
  19. ^ Evans Jr., Doyle J.; Dolores G. Evans. "Escherichia Coli". Medical Microbiology, 4th edition. The University of Texas Medical Branch at Galveston. Archived from the original on 2007-11-02. Retrieved 2007-12-02.
  20. ^ a b c d "Retail Establishments; Annex 3 – Hazard Analysis". Managing Food Safety: A Manual for the Voluntary Use of HACCP Principles for Operators of Food Service and Retail Establishments. U.S. Department of Health and Human Services Food and Drug Administration Center for Food Safety and Applied Nutrition. April 2006. Archived from the original on 2007-06-07. Retrieved 2007-12-02.
  21. PMID 4574421
    .
  22. ^ a b Sabin Russell (October 13, 2006). "Spinach E. coli linked to cattle; Manure on pasture had same strain as bacteria in outbreak". San Francisco Chronicle. Retrieved 2007-12-02.
  23. S2CID 2676938
    .
  24. ^ Thomas R. DeGregori (2007-08-17). "CGFI: Maddening Media Misinformation on Biotech and Industrial Agriculture". Archived from the original on 2007-10-13. Retrieved 2007-12-08.
  25. S2CID 29924171
    .
  26. ^
    doi:10.4141/A02-021
    .
  27. ^ "Germany: Ten die from E.coli-infected cucumbers". BBC News. BBC. 28 May 2011. Retrieved 28 May 2011.
  28. ISBN 978-0-309-08627-1.{{cite book}}: CS1 maint: numeric names: authors list (link
    )
  29. S2CID 15788942
    .
  30. PMID 16000820
    .
  31. PMID 15574966
    .
  32. PMID 9535003
    .
  33. PMID 10598383
    .
  34. PMID 12403105
    .
  35. PMID 14645313
    .
  36. PMID 18061019
    .
  37. ^ a b Identified Virulence Factors of UPEC : Adherence, State Key Laboratory for Moleclular Virology and Genetic Engineering, Beijing. Retrieved July 2011
  38. PMID 17172451
    .
  39. PMID 16056021
    .
  40. S2CID 6900440
    .
  41. PMID 26390983
    .
  42. PMID 24116215
    .
  43. PMID 20534522
    .
  44. S2CID 19619374
    .
  45. PMID 22903521
    .
  46. ISBN 0-8138-0430-2
    , p. 270
  47. PMID 9665978
    .
  48. ^ "Importance of Culture Confirmation of Shiga Toxin-producing Escherichia coli Infection as Illustrated by Outbreaks of Gastroenteritis --- New York and North Carolina, 2005". MMWR. CDC. Retrieved 19 July 2011.
  49. ^ "Recommendations for Diagnosis of Shiga Toxin--Producing Escherichia coli Infections by Clinical Laboratories". MMWR Recommendations and Reports. CDC (USA). Retrieved 19 July 2011.
  50. PMID 16741884
    .
  51. S2CID 27321244
    .
  52. PMID 15337162
    .
  53. PMID 16223952
    .
  54. ^ "HPA Press Statement: Infections caused by ESBL-producing E. coli". Archived from the original on 2011-07-17.
  55. ^ "Therapeutic use of bacteriophages in bacterial infections". Polish Academy of Sciences. Archived from the original on 2006-02-08.
  56. ^ "Medical conditions treated with phage therapy". Phage Therapy Center.
  57. ^ "OmniLytics Announces USDA/FSIS Approval for Bacteriophage Treatment of E. coli O157:H7 on Livestock". OmniLytics. Archived from the original on 2007-09-30. Retrieved 2011-07-17.
  58. ^ "PreForPro: the Science". Deerland Probiotics and Enzymes.
  59. PMID 16483695
    .
  60. ^
    PMID 16425130
    .
  61. ^ "Reducing pathogenic E. coli infection by vaccination". World Poultry. 14 December 2009. Retrieved 10 May 2016.
  62. PMID 17203031
    .
  63. ^ "New cattle vaccine controls E. coli infections". Canada AM. 2007-01-11. Retrieved 2007-02-08.
  64. ^ "Canadian Research Collaboration Produces World's First Food Safety Vaccine: Against E. coli O157:H7" (Press release). Bioniche Life Sciences Inc. 2007-01-10. Archived from the original on 2007-10-11. Retrieved 2007-02-08.
  65. ^ "Researchers develop E. coli vaccine". Physorg.com. Retrieved 2011-06-05.
  66. ^ a b Ehrenberg, Rachel (2018-05-17). "Your blood type might make you more likely to get traveler's diarrhea". Science News. Retrieved 2018-05-18.
  67. PMID 29771685
    .

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Pathogenic_Escherichia_coli&oldid=1218484458#Virulence_properties"