A foodborne outbreak of Vero cytotoxin-producing Escherichia coli O157:H-phage type 8 in hospital

Phylo-diversity of prevalent human E. coli O157:H7 with strains from retailed meat and fish in selected markets in Ibadan Nigeria

Global prevalence of ESBL-biotypes poses a serious threat to public health as a result of severity and morbidity caused by beta-lactam encoded Escherichia coli. Therefore, the prevalent shiga toxigenic Escherichia coli of ESBL variant was investigated in various retailed food animals and cooking materials. A total of 823 samples consisting of raw meat (297) and fish (132) samples retailed at various major markets in Ibadan were collected and 394 swabs were taken from the butchers' processing tables and utensils used in retailing meat and fish. The samples were cultured and biotyped for Escherichia coli. Serological and PCR assay were used to identify O157:H7 variant and antibiotics resistant determinants. Genetic relatedness of characterized E. coli O157 from human and meat products was evaluated with phylogenetic analysis. Of all the isolates, 130 (15.8%) were E. coli and only 8 (1.0) were O157:H7 while 4 (50%) were resistant to one or more antibiotics with resistance index ranging from 0.1 to 0.5. More than 25% E. coli O157:H7 were resistant to Ampicillin, Pefloxacin and Gentamicin and bla_SHV and bla_CTX-M were detected in 1/8 (12.5%) of E. coli O157:H7 and bla_TEM 3/8 (37.5%) respectively. Only 1 genotyped human Escherichia coli .0157:H7 clustered with beef strain There is evidence of blaTEM encoded E. coli O157:H7 causing infection in human from food animals retailed in many markets within various communities. Therefore, urgent surveillance with public health education, food, and environmental hygiene are highly needed to prevent its spread.

Patient safety: this is public health

Avoidable patient harm is a major public health concern, and may already have surpassed heart disease as the leading cause of death in the United States. While the public health community has contributed much to one aspect of patient harm prevention, infection control, the tools and techniques of public health have far more to offer to the emerging field of patient safety science. Patient safety practice has become increasingly professionalized in recent years, but specialist degree programs in the field remain scarce. Healthcare organizations should consider graduate training in public health as an avenue for investing in the professional development of patient safety practitioners, and schools and programs of public health should support further research and teaching to support patient safety improvement.

Microbiological food safety and a low-microbial diet to protect vulnerable people

Low-microbial diets are advised by many institutions for people with neutropenia resulting from treatment with immunosuppressive drugs or medical conditions that increase their susceptibility to foodborne disease. In this article, the main microbiological hazards associated with foods are outlined, and a low-microbial diet in which higher-risk foods are replaced by lower-risk foods is described.

Cattle, weather and water: mapping Escherichia coli O157:H7 infections in humans in England and Scotland

Entero-haemorrhagic Escherichia coli O157:H7 is a zoonotic pathogen, responsible for a relatively small number of food poisoning and illness outbreaks each year, when compared with other food-borne bacteria capable of causing infections in the population. Nevertheless, E. coli O157:H7 is a bacterial pathogen associated with severe human illnesses including bloody diarrhoea and haemolytic uremic syndrome occurring in both outbreak and sporadic settings. In England and Wales approximately 1% of all laboratory-confirmed cases of food poisoning are the result of E. coli O157:H7; however, in Scotland this figure increases to 3%. When the size of the population is taken into account and the rate of E. coli O157:H7 confirmed cases per 100,000 population is examined, the rate of E. coli 0157:H7 infections in Scotland is much greater than England and Wales. The routes of transmission have changed over time, with new routes of transmission such as farm visits emerging. The prevalence of E. coli O157:H7 has a seasonal dependency, with greater faecal shedding of the organism in the warmer months; this is directly mirrored in the increased reporting of E. coli O157:H7 infection among hospitalized patients. This review attempts to suggest why this phenomenon occurs, paying particular attention to weather, animal movement and private water supplies.

Microbiological safety of food in hospitals and other healthcare settings

Cases and outbreaks of foodborne infection in healthcare settings can result in serious illness, wastage of expensive medical treatments, spread of infection to other patients and staff and disruption of services. Providing nutritious meals for vulnerable people in healthcare settings involves a systematic approach to microbiological safety, as provided by hazard analysis and critical control point (HACCP) principles. The types of food served in healthcare settings should be selected to minimise the risk of foodborne infection.

Escherichia coli O157: what every internist and gastroenterologist should know

Infections with Escherichia coli O157:H7 have gained media attention in recent years because of cases associated with unusual sources (eg, produce and swimming pools). Although most adults recover without sequelae, children and the elderly are more likely to develop complications (eg, hemolytic uremic syndrome and death). The diagnosis typically has been made by culture; however, newer hand-held immunoassays and polymerase chain reaction technology have led to more rapid detection of this important pathogen in stools, food, and water. Treatment is largely supportive; nonetheless, new methods to neutralize or bind toxin, such as probiotics, monoclonal antibodies, and recombinant bacteria, are showing promise to treat patients infected with E. coli O157:H7. The role of antibiotics in relation to this condition remains unclear.

Role for flagella but not intimin in the persistent infection of the gastrointestinal tissues of specific-pathogen-free chicks by shiga toxin-negative Escherichia coli O157:H7

Shiga toxin (Stx)-positive Escherichia coli O157:H7 readily colonize and persist in specific-pathogen-free (SPF) chicks, and we have shown that an Stx-negative E. coli O157:H7 isolate (NCTC12900) readily colonizes SPF chicks for up to 169 days after oral inoculation at 1 day of age. However, the role of intimin in the persistent colonization of poultry remains unclear. Thus, to investigate the role of intimin and flagella, which is a known factor in the persistence of non-O157 E. coli in poultry, isogenic single- and double-intimin and aflagellar mutants were constructed in E. coli O157:H7 isolate NCTC12900. These mutants were used to inoculate (10(5) CFU) 1-day-old SPF chicks. In general, significant attenuation of the aflagellate and intimin-aflagellate mutants, but not the intimin mutant, was noted at similar time points between 22 and 92 days after inoculation. The intimin-deficient mutant was still being shed at the end of the experiment, which was 211 days after inoculation, 84 days more than the wild type. Shedding of the aflagellar and intimin-aflagellar mutants ceased 99 and 113 days after inoculation, respectively. Histological analysis of gastrointestinal tissues from inoculated birds gave no evidence for true microcolony formation by NCTC12900 or intimin and aflagellar mutants to epithelial cells. However, NCTC12900 mutant derivatives associated with the mucosa were observed as individual cells and/or as large aggregates. Association with luminal contents was also noted. These data suggest that O157 organisms do not require intimin for the persistent colonization of chickens, whereas flagella do play a role in this process.

Virulence typing of Escherichia coli using microarrays

We describe a microarray based broad-range screening technique for Escherichia coli virulence typing. Gene probes were amplified by PCR from a plasmid bank of characterised E. coli virulence genes and were spotted onto a glass slide to form an array of capture probes. Genomic DNA from E. coli strains which were to be tested for the presence of these virulence gene sequences was labelled with fluorescent cyanine dyes by random amplification and then hybridised against the array of probes. The hybridisation, washing and data analysis conditions were optimised for glass slides, and the applicability of the method for identifying the presence of the virulence genes was determined using reference strains and clinical isolates. It was found to be a sensitive screening method for detecting virulence genes, and a powerful tool for determining the pathotype of E. coli. It will be possible to expand and automate this microarray technique to make it suitable for rapid and reliable diagnostic screening of bacterial isolates.