NAME: Escherichia coli, enteroinvasive
CHARACTERISTICS: Enteroinvasive Escherichia coli (EIEC) are in the family Enterobacteriaceae Footnote 2. They are Gram negative, rod shaped, non-spore forming, motile with peritrichous flagella or nonmotile, grow on MacConkey agar (colonies are 2 to 3 mm in diameter and red or colorless), and are capable of aerobic or anaerobic growth Footnote 3. Strains belonging to EIEC are biochemically, genetically, and pathogenically closely related to Shigella spp. Footnote 1.
PATHOGENICITY/TOXICITY: EIEC causes bacillary dysentery Footnote 1, an acute ulcerative infection of the large intestine Footnote 1, Footnote 4. EIEC invade cells of the colon and causes watery diarrhea (might be bloody), fever, and abdominal cramps Footnote 2, Footnote 5. In severe cases, the bacteria may attack the colonic mucosa, invading epithelial cells, multiplying, and causing ulceration of the bowel Footnote 1.
EPIDEMIOLOGY: EIEC is endemic in most developing countries and may cause occasional outbreaks in industrialized countries Footnote 4. Species of Shigella are the major cause of bacillary dysentery, although up to 10% of cases are caused by enteroinvasive E. coli. EIEC are rare in United States and Canada, and are less common than ETEC and EPEC strains in the developing world Footnote 2. Three large outbreaks in the United States have been reported. EIEC infections primarily affect children under 5 years living in developing countries Footnote 6.
HOST RANGE:Humans Footnote 2.
INFECTIOUS DOSE: 106-1010 organisms Footnote 4.
MODE OF TRANSMISSION: EIEC are spread by the fecal/oral route Footnote 1, Footnote 7. Contaminated food and water are the usual vehicles for the spread Footnote 5, Footnote 7. Food-borne outbreaks have occurred Footnote 7. Person-to person transmission can also occur Footnote 1.
INCUBATION PERIOD: The incubation period is between 2-48 hours with an average of about 18 hours Footnote 8.
RESERVOIR: Humans are the only known reservoir Footnote 6.
ZOONOSIS: None reported Footnote 9.
DRUG SUSCEPTIBILITY/RESISTANCE: Susceptible to carbapenem, fosfomycin-trometanol and nitrofurantoin. E. coli can be resistant to chloramphenicol, β lactams, nalidixic acid, ampicillin and ciprofloxacin Footnote 1. Fluoroquinolones such as ciprofloxacin enhance toxin production.
SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to a combination of 2,2-dibromo-2-cyanoacetamide (DBA) with sodium iodide (20:80 parts), iodine, 2 % glutaraldehyde, quaternary ammonium (20°C, 0.5 min), hypochlorite (0.525%, 20°C, 0.5 min), phenolics (20°C, 0.5 min), and ethyl alcohol (70%, 20°C, 0.5 min) Footnote 10-Footnote 12.
SURVEILLANCE: Monitor for symptoms. Stool culture Footnote 5, immunoassays Footnote 2, and nucleic acid-based assays Footnote 2 are used for detection of EIEC. As with Shigella spp., the loci most frequently sought in molecular tests (PCR and DNA hybridization methods) are ipaH and the invasion-associated locus (ial) Footnote 15, Footnote 16.
Note: All diagnostic methods are not necessarily available in all countries.
FIRST AID TREATMENT: Treatment with trimethoprim/sulfamethoxazole (TMP-SMX) or quinolones reduces the duration of diarrhea Footnote 6. Treatment of fluid and electrolyte loss is usually achieved through oral rehydration Footnote 7, Footnote 9. The use of the World Health Organization Oral Rehydration Salts (ORS) solution has been recommended Footnote 7. Intravenous rehydration may be necessary for infants, individuals with excessive vomiting, or those with severe dehydration. Bismuth subsalicylate may decrease the amount of diarrhea and the duration of disease. Antimicrobial therapy is generally not indicated, because of the self-limited nature of this disease.
IMMUNIZATION: None Footnote 7.
PROPHYLAXIS: TMP-SMX is recommended for a short term (< 2 weeks) for those at a high risk of disease Footnote 6. Bismuth subsalicylate provides some prophylactic benefit, but should not be used as a substitute for other preventive measures Footnote 7.
LABORATORY ACQUIRED INFECTIONS: Twelve cases of laboratory acquired infections with E. coli have been reported, the majority of which have been caused by E.coli enterohemorrhagic (EHEC) Footnote 17.
PRIMARY HAZARD: Ingestion Footnote 17.
SPECIAL HAZARD: None.
RISK GROUP CLASSIFICATION: Risk Group 2 Footnote 19.
CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, or cultures Footnote 20.
PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes Footnote 20.
OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC) Footnote 20. The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities.
SPILLS: Allow aerosols to settle and, wearing protective clothing, gently cover spill with paper towels and apply an appropriate disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up Footnote 20.
DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism by autoclave, chemical disinfection, gamma irradiation, or incineration before disposing Footnote 20.
STORAGE: The infectious agent should be stored in leak-proof containers that are appropriately labeled Footnote 20.
REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.
UPDATED: December 2011
PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada
Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.
Public Health Agency of Canada, 2011