Monitoring of Hemorrhagic Colitis
Monitoring of Haemorrhagic Colitis Causative Agent E.coli 0157:H7 in Russia: Improvement of Methods of Diagnosis and Prevention of Infection
Tech Area / Field
- MED-DIS/Disease Surveillance/Medicine
- MED-DID/Diagnostics & Devices/Medicine
8 Project completed
Senior Project Manager
Pobedimskaya D D
State Research Center for Applied Microbiology, Russia, Moscow reg., Obolensk
- Central Research Institute of Epidemioloigy, Russia, Moscow
- Universität Würzburg / Institute for Hygiene ana Microbiology, Germany, Würzburg\nSwedish Institute for Infectious Disease Control (SMI), Sweden, Solna\nRobert-Koch-Institute, Germany, Berlin\nInstitut Pasteur, France, Paris\nNational Institute of Infectious Diseases, Japan, Tokyo\nUniversity of Liverpool, UK, Liverpool
Project summaryThe objective of the project is the epidemiological and epizootological analyses of the morbidity rate of acute intestinal infections (All) caused by E.coli 0157: H7 and other enterohaemorrhagic E.coli strains, molecular-biological monitoring of the causative agents, development and improvement of the methods and preparations to make a diagnosis and to identify the microbes
The problem of E.coli 0157: H7 infection has now got international character. Its decision in global scale largely depends on comprehensive monitoring of the morbity rate of the disease and its causative agent in each separately taken country, efficiency of antiepidemic measures and operative exchange of the information. In this respect Russian Federation much lags behind the world community. Owing to this, information on the spread of E.coli 0157: H7 infection at the territory of Russia is practically absent.
Within the last years acute intestinal infections (All) have been widely spread in the Russian Federation. 35 and 137 outbreaks of All transmitted through water and food, respectively, were registered during 1994-1995. As the result of these outbreaks more than 19 thousand people had fallen ill. 786 people, of whom 60% were children at the age up to 14 years, were injured in Russia in the first quarter of 1996. Most cases of All, including those complicated with hemolytic-uremic syndrome (HUS), remain to be of unknown etiology. With high probability it is possible to consider, that among the unidentified All there is an infection provoked by enterohaemorrhagic Escherichia coli of serotype 0157: H7. Sporadic cases of HUS complicated haemorrhagic colitis (HC) caused by E.coli 0157:H7 and registered for the first time by the project authors in children and persons of elderly age is a good evidence in favour of this statement. At present day in Russia the production of commercial preparations to make a diagnosis of the infection is far from being perfect. By virtue of this, no data on epidemiology and epizootology of E. coli 0157:H7 and other enterohaemorrhagic Escherichiae are available. It is completely obvious, that the research of enterohaemorrhagic E.coli strains of epidemic significance, ways of their propagation and natural reservoirs at the territory of Russian Federation as well as development and improvement of diagnostic methods and preparations and methods to identify the microbe are important medical problems.
There are some preliminary results, which may be helpful for project implementation:
- a collection of clinical and epizootic enter о virulent Escherichiae, including E.coli 0157: H7, was established;
- differentiation of collection strains with regard to cultural -morphological, biochemical and serological properties was performed;
- spectra and levels of drug resistance of clinical and epizootic E.coli strains were determined;
- test- system for express identification of E.coli 0157: H7 was developed on the basis of latex-agglutination reaction.
Technical Approach and Methodology
Complex study of the epidemiological situation with regard to 0157:H7 escherichiosis, revealing of the reasons and conditions of this infection spread status of diagnosis and preventive maintenance of it will be the starting point of the investigation.
The following methodical approaches will be used within the project proposed.
Epidemiological and epizootological monitoring
- accumulation and analysis of epizootological and epidemiological information on 0157: H7 and other O-escherichioses in different countries of the world, including Russia and Japan
- identification of EHEC strains and diagnostics of E. coli 0157 infections in outbreaks and sporadic cases.
Comparative analysis of biological properties of E.coli 0157: H7 strains, revealed in different countries of the world (Russia, Japan)
- analysis of cultural -morphological and biochemical properties of the strains by the methods of general and clinical bacteriology;
- studies on colicynogenicity and hemolytic activity;
- studies on the virulence of strains for laboratory animals;
- studies on toxigenic properties of the strains on newborn sucking pigs;
- estimation of adhesive and toxigenic properties of the strains on tissue cell culture;
- determination of plasmid profile of the strains; isolation and analysis of plasmid DNA;
- antigenic characteristics of the strains by immunoblotting with specific sera;
- determination of srug resistance of the strains in vitro by microbiological methods. Genetic typing of E.coli 0157: H7 strains
- analysis of chromosomal DNA by using a set of restriction endonucleases with subsequent estimation of restriction fragment length polymorphism
- PCR typing by using specific and universal primers.
Development of methods of express identification of E. coli O157: H7
- latex test - system for the detection of 0157, H7 antigens, SLT-toxins;
- PCR with synthetic oligonucleotide primers complementary to the nucleotide sequences of tested genes;
- immunofluorescence reaction and immunoenzymatic analysis for the detection of 0157 and H7 antigens;
- hemagglutination neutralization reaction for the detection of 0157 antigen in fecal mass.
Both group cases of All with unidentified etiology and sporadic cases of infections registered by sanitary-epidemiological services in different regions of the country will be subjected to inspection with the purpose of the diagnosis of HC, caused by E.coli 0157: H7 and other enterohaemorrhagic Escherichia. Special attention will be addressed to the cases of All, accompanying with bloody diarrhea and HUS. Since farming animals are the main reservoirs of enterohaemorrhagic Escherichiae, circulation of these microorganisms in herds and farms will be investigated.
The following results are expected:
- epidemiological situation on escherichiosis 0157: H7 at the territory of the Russian Federation will be evaluated;
- data on the distribution of enterohaemorrhagic Escherichiae in farming animals will be obtained;
- bank of enterohaemorrhagic and other enterovirulent Escherichiae will be established;
- pheno- and genotypical characteristics of E.coli 0157: H7 strains isolated at the territory of Russia and Japan will be obtained;
- possibility of using methods of genome dactyloscopy for the analysis of epidemiological and epizootological situations with regard to E.coli 0157: H7 escherichiosis in Russia will be investigated;
- effective methods of diagnosis of E.coli 0157: H7 infection in humans and animals and identification of the causative agent in fecal mass, foods and other objects of external environment will be developed;
- recommendations on the reduction of bacterium carrying among farming animals will be developed;
- methods of the improvement of preventive measures and methods of treatment of E.coli 0157: H7 escherichiosis will be developed.
Role of foreign collaborators
- rendering of advisory and methodical help;
- exchange of scientific information;
- joint molecular-biological researches.