Eba ppt.pptx

Eba ppt.pptx

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  HARAMAYA UNIVERSITY COLLEGE OFVETERINARY MEDICINE Power point presentation of REVIEW ON ESCHERICHIA COLI O157:H7 GIVEN EMPHASIS IN ETHIOPIA: AN EMERGING FOODBORNE PATHOGEN Prepared by: EBA TEFERI
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  REVIEW ON ESCHERICHIACOLI O157:H7 GIVEN EMPHASIS IN ETHIOPIA: AN EMERGING FOODBORNE PATHOGEN Overview Introduction Taxonomy Morphology Characteristics Epidemiology Pathogenesis Clinical Significance Diagnostic Methods Risk Factors Antimicrobial Resistance Conclusion and Recommendations
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  INTRODUCTION • Food-borne diseasesare important public health and economic burden. • Result in considerable morbidity and mortality rate. • The severity is higher among developing countries due to:- Changes in eating habits and widespread habit of raw beef consumption Poor food handling and sanitation practices Inadequate food safety laws, weak regulatory systems, Lack of financial resources and Lack of awareness about proper food handling which creates a conducive environment for the spread of food-borne and food poisoning etiologic agents.
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  CON’T… Escherichia coli isamong the most challenging Enterobacteriaceae group of bacterial meat contaminant worldwide. Most E. coli strains do not cause diseases and are actually part of the normal flora. Some strains of E. coli such as E. coli O157:H7 are capable of producing disease when the immune system is compromised or as a result from an environmental exposure. Among the intestinal pathogens there are six well-described E. coli categories: entero-pathogenic E. coli(EPEC), entero-haemorrhagic E. coli (EHEC), entero-toxigenic E. coli (ETEC), entero-aggregative E. coli(EAEC), entero-invasive E. coli (EIEC) and diffusely adherent E. coli (DAEC).
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  CONT… • E. coliserotype O157:H7 is:- an enterohaemorrhagic strain. initially recognized in the United States of America as a cause of food- borne illness and has now emerged as an important enteric pathogen of considerable public health significance. • In Ethiopia, E. coli O157:H7 was isolated from:-  different sample sources  humans  food animals and  contact surfaces • Most of the studies also showed that E. coli O157:H7 isolated to be resistant to varieties of antimicrobial agents. Therefore the objective of this paper is to review on a foodborne pathogen E. coli O157:H7.
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  ESCHERICHIA COLI O157:H7:AN EMERGING FOODBORNE PATHOGEN Taxonomy • Escherichia coli is:- The most common species of facultative anaerobe. Belongs to family Enterobacteriaceae Genus Escherichia and Species coli Has a number of serovars (160 antigenic types O, 56 types H, 80 types K/Vi). Morphology • Escherichia coli are:-  Gram negative bacteria  Facultative anaerobic  Non sporulating organism  The cells are about 2μm long and 0.5μm in diameter  Some strains possess flagella and motile. Eg: O157: H7 strain
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  CON’T…
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  Characteristics of E.coli O157: H7 • Escherichia coli can be characterized by stereotyping. • The serotype is defined by :-  O-antigen (Ohne),  Lipopolysaccharide (LPS) in the outer membrane, and  H-antigen (Hauch) consisting of flagella protein. • May also include the K antigen (Kapsel) and the F-antigen (Fimbriae). • The three phenotypic differences between E. coli O157:H7 and other E. coli are:-  inability to ferment sorbitol,  lack of β–glucuronidase enzyme and  weak or no growth at temperatures above 44 °C.
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  Epidemiology of E.coli O157:H7 • Escherichia coli O157:H7 infections occur worldwide. Reservoir of infections • Livestock are the most important reservoir of E. coli O157:H7. • Cattle being the principal sources, followed by sheep and goat. Mode of Transmission  via fecal-oral route. Fecal contamination of other food products. Consumption of contaminated food and water.  direct contact with infected animals.
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  Pathogenesis • The pathogenicityof E. coli O157:H7 is associated with a number of virulence factors;-  Locus of Enterocyte Effacement (LEE),  Shiga toxins (Stx) and  The plasmid (pO157)
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  Clinical Significance ofE. coli O157:H7 in Humans and Farm Animals In Humans • It forms three types of syndromes:- hemorrhagic colitis (HC), hemolyticuremic syndrome (HUS) and thrombocytic thrombocytopenic purpura (TTP). • Extra renal signs including CNS involvement with lethargy, irritability and seizures are common. • Adhesion of bacteria to the host bowel mucosa induces subsequent histo-pathologic lesion defined as “attaching and effacing” (A/E).
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  In Livestock • Escherichiacoli causes, three main kinds of disease in animals:-  urinary tract infections  neonatal meningitis and  diarrheal diseases. • They are mostly associated with colibacillosis in neonate. • In addition, EHEC O157:H7 causes:- • more rapid and severe neurological disease in suckling neonates. • edema disease in pig • haemorrhagic entero colitis in calves and • post weaning diarrhoea in pigs. CON’T…
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  Escherichia coli O157:H7Identified From Apparently Health and Foods of Animal Origin E. coli O157:H7 isolated from food animal • Food of animal origin (milk and meat) can become contaminated with bacteria during food processing or slaughtering. • Contaminated raw milk and undercooked beef products were implicated in outbreaks of E. coli O157:H7 infections. • Cattle are the primary reservoir of E. coli O157:H7 and an important source of human infection and • Undercooked ground beef and unpasteurized milk being common vehicles of the pathogen transmission.
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  CON’T… E. coli O157:H7isolated from poultry • Poultry meat sometimes has E. coli O157:H7 on its surface and • These bacteria do persist in the ceca of experimentally infected chicks for as long as 11 months. • Escherichia species in liquid egg products are of major public health concern.
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  Diagnostic Methods usedfor identification of E. coli O157:H7 in Ethiopia • Researchers in Ethiopia reported the use of several bacterial isolation procedures. Isolation of the agent on general media. eg. McConkey, followed by EMB and biochemical methods. Very few of them use tests such as molecular biology based technologies such as: polymerase chain reaction (PCR). • There is no single technique that can be used to isolate all EHEC serotypes.
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  Risk Factors AssociatedWith Occurrence of E.coli O157:H7 in Animals and Animal Products • Understanding the epidemiology of this organism requires knowledge of:- where these bacteria live and grow in nature (their reservoir) and how humans come into contact with them. • Ruminants have been identified as the major reservoir of E.coli O157:H7. • Animals acquired these bacteria from meat, foods or water contaminated by fecal material from ruminants. • Raw meat and its products are commonly consumed in traditional Ethiopian diets.
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  Antimicrobial Resistance Patternsof E. coli O157:H7 Isolates in Ethiopia • Antibiotics are commonly used in livestock for the treatment, prevention of disease and to increase growth. • Antibiotic resistance is the result of inappropriate antibiotic use. • Most of antimicrobials are not commonly used in Ethiopia in the treatment of animals that served as a source of meat. • The susceptibility might have contributed to the effectiveness of these antimicrobials mostly against Gram negative bacteria. • From recent studies all of the E. coli O157:H7 isolates were resistant to Amoxicillin while intermediate resistance to Cefoxitine and Nitrofurantoin.
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  CONCLUSION AND RECOMMENDATIONS •Escherichia coli is a food borne pathogen causing a major public health problem in Ethiopia. • The agents was present in the feces, intestinal mucosal swab, carcasses swab and cut board at municipal abattoir and butcher houses. • This pathogen was isolated from carcasses, from the inside parts that indicated the presence of carcass contamination during slaughter operations and at the butcher house the presence of E. coli O157: H7 due to environmental contamination. • The use of antimicrobials in food animals produces resistant bacteria. • These type of bacteria were susceptible to most of the drugs used and multi drug resistance was occurred obviously.
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  CON’T… Based on theabove conclusions the following recommendations are forwarded:-  A thorough hygienic practice should be considered at the time of slaughtering of animals.  Hazard Analysis of Critical Control Points at every stage of the meat supply chain, from the farm through to the abattoir, the retailer, and to those involved with the handling to and processing of such raw food items products in the home environment should be practiced.  Additionally targeted intervention strategies or technologies, like E. coli vaccine or feed additives and awareness creation to the public on sanitary practices should be applied.  Study on E. coli and its characteristics with an aim to reduce the human hazard caused by this emerging pathogen is highly needed.  Public health regulatory agency has to be in place to ensure wholesomeness and safety of food of animal origin for human consumption.
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  THANK YOU FOR YOUR PATIENCE!!!.