Emerging Foodborne Pathogens: Escherichia coil O157:H7 as a Model of Entry of a New Pathogen into the Food Supply of the Developed World

Abstract

There would appear to be little argument that the large outbreaks of E. coli O157:H7 which have occurred since the early 1980s represent a distinct, new phenomenon. The number of reported cases have increased dramatically, starting from zero in 1981; however, it is also clear that this increase in reported cases is in part an artifact of improved surveillance and reporting. Available data suggest that E. coli O157:H7 infections were present prior to 1982, although numbers appear to have been small. At a molecular level, the organism shows evidence of clonal origin, but there is not the striking clonality, with virtually identical pulsed-field gel electrophoresis and ribotyping patterns, which has been seen in situations such as the emergence of Vibrio cholerae O139 Bengal in the Indian subcontinent in 1992 or the introduction of V. cholerae O1 into naïve populations in South America in 1991 (127-129). Findings are more consistent with the image of an organism which arose from a common ancestor, but which has had time to become distributed geographically and to show some evidence of genetic divergence. While this is an "emerging" infection, at least in terms of its distribution and public recognition, it is unlikely that it will be possible to identify the "first" O157:H7 case or to track the clonal spread of the organism through cattle or human populations.

Microbiological Quality Assessment of Vitamin B Syrups and Antibiotic Susceptibility Profile of the Isolated Escherichia coli

“…In rare cases, virulent strains are also responsible for hemolytic-uremic syndrome (HUS), peritonitis, mastitis, and septicemia. During the two decades, several outbreak of gastrointestinal illness have occurred by food borne pathogenic E. coli [3]. E. coli and other members of Enterobacteriaceae are important reservoirs of transferable antibiotic resistance [4].…”

Detecção de Escherichia coli O157:H7 inoculada experimentalmente em amostras de leite cru por método convencional e PCR multiplex

“…Dentre as bactérias analisadas, apenas E. coli O157:H7 apresentou os produtos de amplificação esperados, indicando total especificidade da técnica para detecção de E. coli O157:H7, em concordância com o trabalho de Hu et al (1999 A sensibilidade e especificidade do método são particularmente importantes quando se analisam alimentos. Para E. coli O157:H7, a dose infectante pode ser inferior a 10UFC (Armstrong et al, 1996). Embora não existam padrões microbiológicos estabelecidos para E. coli O157:H7 na legislação brasileira, a presença de 1 a 10UFC/ml pode ser capaz de causar doença no homem e, desse modo, não deve ser permitida a sua presença em nenhuma amostra de alimento (ausência em 25g ou 25ml No caso do leite cru com alta contaminação bacteriana, a sensibilidade foi menor para os dois métodos, sendo o método convencional mais sensível que a PCR na detecção de E. coli O157:H7 (Tab.…”

Behavior and changes in cell morphology ofEscherichia coliO157:H7 in liquid medium and skim milk in the presence of caffeine

“…E. coli O157:H7 has been implicated in outbreaks from a variety of foods including raw milk, undercooked ground beef, fermented meat, and lettuce (Ackers et al, 1998;Armstrong, Hollingsworth, & Morris, 1996;Hancock, Besser, Rice, Herriott, & Tarr, 1997;Mao, Doyle, & Chen, 2001). Milk contamination occurs usually during milking, although it is possible during storage and transportation.…”