An outbreak of Escherichia coli O157:H7 infections among visitors to a dairy farm

Detection of multidrug-resistant Shiga toxin-producing Escherichia coli in some food products and cattle faeces in Al-Sharkia, Egypt: one health menace

BACKGROUND

Shiga toxin-producing Escherichia coli (STEC) is a zoonotic pathogen, that is transmitted from a variety of animals, especially cattle to humans via contaminated food, water, feaces or contact with infected environment or animals. The ability of STEC strains to cause gastrointestinal complications in human is due to the production of Shiga toxins (sxt). However, the transmission of multidrug-resistance STEC strains are linked with a severity of disease outcomes and horizontal spread of resistance genes in other pathogens. The result of this has emerged as a significant threat to public health, animal health, food safety, and the environment. Therefore, the purpose of this study is to investigate the antibiogram profile of enteric E. coli O157 isolated from food products and cattle faeces samples in Zagazig City, Al-Sharkia, Egypt, and to reveal the presence of Shiga toxin genes stx1 and stx2 as virulence factors in multidrug-resistant isolates. In addition to this, the partial 16S rRNA sequencing was used for the identification and genetic recoding of the obtained STEC isolates.

RESULTS

There was a total of sixty-five samples collected from different geographical regions at Zagazig City, Al-Sharkia-Egypt, which were divided into: 15 chicken meat (C), 10 luncheon (L), 10 hamburgers (H), and 30 cattle faeces (CF). From the sixty-five samples, only 10 samples (one from H, and 9 from CF) were identified as suspicious E. coli O157 with colourless colonies on sorbitol MacConkey agar media with Cefixime- Telurite supplement at the last step of most probable number (MPN) technique. Eight isolates (all from CF) were identified as multidrug-resistant (MDR) as they showed resistance to three antibiotics with multiple antibiotic resistance (MAR) index ≥ 0.23, which were assessed by standard Kirby-Bauer disc diffusion method. These eight isolates demonstrated complete resistance (100%) against amoxicillin/clavulanic acid, and high frequencies of resistance (90%, 70%, 60%,60%, and 40%) against cefoxitin, polymixin, erythromycin, ceftazidime, and piperacillin, respectively. Those eight MDR E. coli O157 underwent serological assay to confirm their serotype. Only two isolates (CF8, and CF13), both from CF, were showed strong agglutination with antisera O157 and H7, as well as resistance against 8 out of 13 of the used antibiotics with the highest MAR index (0.62). The presence of virulence genes Shiga toxins (stx1 and stx2) was assessed by PCR technique. CF8 was confirmed for carrying stx2, while CF13 was carrying both genes stx1, and stx2. Both isolates were identified by partial molecular 16S rRNA sequencing and have an accession number (Acc. No.) of LC666912, and LC666913 on gene bank. Phylogenetic analysis showed that CF8, and CF13 were highly homologous (98%) to E. coli H7 strain, and (100%) to E. coli DH7, respectively.

CONCLUSION

The results of this study provides evidence for the occurrence of E. coli O157:H7 that carries Shiga toxins stx1 and/or stx2, with a high frequency of resistance to antibiotics commonly used in human and veterinary medicine, in Zagazig City, Al-Sharkia, Egypt. This has a high extent of public health risk posed by animal reservoirs and food products with respect to easy transmission causing outbreaks and transfer resistance genes to other pathogens in animal, human, and plants. Therefore, environmental, animal husbandry, and food product surveillance, as well as, clinical infection control, must be strengthened to avoid the extra spread of MDR pathogens, especially MDR STEC strains.

Phylogenetic Analysis of Escherichia coli Isolated from Australian Feedlot Cattle in Comparison to Pig Faecal and Poultry/Human Extraintestinal Isolates

The similarity of commensal Escherichia coli isolated from healthy cattle to antimicrobial-resistant bacteria causing extraintestinal infections in humans is not fully understood. In this study, we used a bioinformatics approach based on whole genome sequencing data to determine the genetic characteristics and phylogenetic relationships among faecal Escherichia coli isolates from beef cattle (n = 37) from a single feedlot in comparison to previously analysed pig faecal (n = 45), poultry extraintestinal (n = 19), and human extraintestinal E. coli isolates (n = 40) from three previous Australian studies. Most beef cattle and pig isolates belonged to E. coli phylogroups A and B1, whereas most avian and human isolates belonged to B2 and D, although a single human extraintestinal isolate belonged to phylogenetic group A and sequence type (ST) 10. The most common E. coli sequence types (STs) included ST10 for beef cattle, ST361 for pig, ST117 for poultry, and ST73 for human isolates. Extended-spectrum and AmpC β-lactamase genes were identified in seven out of thirty-seven (18.9%) beef cattle isolates. The most common plasmid replicons identified were IncFIB (AP001918), followed by IncFII, Col156, and IncX1. The results confirm that feedlot cattle isolates examined in this study represent a reduced risk to human and environmental health with regard to being a source of antimicrobial-resistant E. coli of clinical importance.

Prevalence and Implications of Shiga Toxin-Producing E. coli in Farm and Wild Ruminants

Shiga-toxin-producing Escherichia coli (STEC) is a food-borne pathogen that causes human gastrointestinal infections across the globe, leading to kidney failure or even death in severe cases. E. coli are commensal members of humans and animals' (cattle, bison, and pigs) guts, however, may acquire Shiga-toxin-encoded phages. This acquisition or colonization by STEC may lead to dysbiosis in the intestinal microbial community of the host. Wildlife and livestock animals can be asymptomatically colonized by STEC, leading to pathogen shedding and transmission. Furthermore, there has been a steady uptick in new STEC variants representing various serotypes. These, along with hybrids of other pathogenic E. coli (UPEC and ExPEC), are of serious concern, especially when they possess enhanced antimicrobial resistance, biofilm formation, etc. Recent studies have reported these in the livestock and food industry with minimal focus on wildlife. Disturbed natural habitats and changing climates are increasingly creating wildlife reservoirs of these pathogens, leading to a rise in zoonotic infections. Therefore, this review comprehensively surveyed studies on STEC prevalence in livestock and wildlife hosts. We further present important microbial and environmental factors contributing to STEC spread as well as infections. Finally, we delve into potential strategies for limiting STEC shedding and transmission.

Comparison of approaches for source attribution of ESBL-producing Escherichia coli in Germany

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia (E.) coli have been widely described as the cause of treatment failures in humans around the world. The origin of human infections with these microorganisms is discussed controversially and in most cases hard to identify. Since they pose a relevant risk to human health, it becomes crucial to understand their sources and the transmission pathways. In this study, we analyzed data from different studies in Germany and grouped ESBL-producing E. coli from different sources and human cases into subtypes based on their phenotypic and genotypic characteristics (ESBL-genotype, E. coli phylogenetic group and phenotypic antimicrobial resistance pattern). Then, a source attribution model was developed in order to attribute the human cases to the considered sources. The sources were from different animal species (cattle, pig, chicken, dog and horse) and also from patients with nosocomial infections. The human isolates were gathered from community cases which showed to be colonized with ESBL-producing E. coli. We used the attribution model first with only the animal sources (Approach A) and then additionally with the nosocomial infections (Approach B). We observed that all sources contributed to the human cases, nevertheless, isolates from nosocomial infections were more related to those from human cases than any of the other sources. We identified subtypes that were only detected in the considered animal species and others that were observed only in the human population. Some subtypes from the human cases could not be allocated to any of the sources from this study and were attributed to an unknown source. Our study emphasizes the importance of human-to-human transmission of ESBL-producing E. coli and the different role that pets, livestock and healthcare facilities may play in the transmission of these resistant bacteria. The developed source attribution model can be further used to monitor future trends. A One Health approach is necessary to develop source attribution models further to integrate also wildlife, environmental as well as food sources in addition to human and animal data.

Incidence and cost of haemolytic uraemic syndrome in urban China: a national population-based analysis

Background

Haemolytic uraemic syndrome (HUS) is a severe syndrome that causes a substantial burden for patients and their families and is the leading cause of acute kidney injury in children. However, data on the epidemiology and disease burden of HUS in Asia, including China, are limited. We aimed to estimate the incidence and cost of HUS in China. 

Methods

Data about HUS from 2012 to 2016 were extracted from the Urban Employee Basic Medical Insurance (UEBMI) and Urban Resident Basic Medical Insurance (URBMI) databases. All cases were identified by ICD code and Chinese diagnostic terms. The 2016 national incidence rates were estimated and stratified by sex, age and season. The associated medical costs were also calculated.

Results

The crude incidence of HUS was 0.66 per 100,000 person-years (95% CI: 0.35 to 1.06), and the standardized incidence was 0.57 (0.19 to 1.18). The incidence of HUS in males was slightly higher than that in females. The age group with the highest incidence of HUS was patients < 1 year old (5.08, 95% CI: 0.23 to 24.87), and the season with the highest incidence was autumn, followed by winter. The average cost of HUS was 2.15 thousand US dollars per patient, which was higher than the national average cost for all inpatients in the same period.

Conclusions

This is the first population-based study on the incidence of HUS in urban China. The age and seasonal distributions of HUS in urban China are different from those in most developed countries, suggesting a difference in aetiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02746-2.

Zoonotic bacteria in clinically healthy goats in petting zoo settings of zoological gardens in Germany

Goats and other small ruminants are frequently used as contact animals in petting zoo settings of zoological gardens. However, they are capable to carry a broad spectrum of zoonotic pathogens without clinical signs. In this study, we analysed the presence of different zoonotic pathogens in 300 clinically healthy goats from 14 zoological gardens in Germany. Rectal and nasal swabs were investigated with a series of cultural and molecular techniques. In addition, vaginal swabs of the 230 female goats were investigated for the presence of Coxiella burnetii by real-time PCR. Antibodies against C. burnetii were tested in milk and serum by ELISA. Campylobacter spp. were found in 22.7%, Shiga-toxigenic Escherichia coli in 20.0% and Arcobacter spp. were found in 1.7% of the tested 300 goats after culture from rectal swabs and subsequent PCR. One sample contained an Escherichia fergusonii isolate with a bla_CTX-M-1 -encoded extended-spectrum beta-lactamase phenotype. Neither Yersinia spp. nor Salmonella spp. were found. Nasal swabs of 20.7% of the goats yielded Staphylococcus aureus including one mecC-positive methicillin-resistant isolate. Neither Yersinia spp. nor Salmonella spp. were found, and none of the 230 vaginal swabs was positive for C. burnetii. Attempts to detect dermatophytes failed. In conclusion, a possible risk of transmission of zoonotic bacteria from goats in petting zoos to visitors should be considered. Appropriate information and facilities for hand washing and disinfection should be provided in all zoological gardens using goats as contact animals due to the regular presence of zoonotic bacteria in the collection.

Examining the Environmental Impacts of the Dairy and Baby Food Industries: Are First-Food Systems a Crucial Missing Part of the Healthy and Sustainable Food Systems Agenda Now Underway?

Food systems are increasingly being understood as driving various health and ecological crises and their transformation is recognised as a key opportunity for planetary health. First-food systems represent an underexplored aspect of this transformation. Despite breastfeeding representing the optimal source of infant nutrition, use of commercial milk formula (CMF) is high and growing rapidly. In this review, we examine the impact of CMF use on planetary health, considering in particular its effects on climate change, water use and pollution and the consequences of these effects for human health. Milk is the main ingredient in the production of CMF, making the role of the dairy sector a key area of attention. We find that CMF use has twice the carbon footprint of breastfeeding, while 1 kg of CMF has a blue water footprint of 699 L; CMF has a significant and harmful environmental impact. Facilitation and protection of breastfeeding represents a key part of developing sustainable first-food systems and has huge potential benefits for maternal and child health.

An Investigation of Potential Health Risks from Zoonotic Bacterial Pathogens Associated with Farm Rats

BACKGROUND

The 21st century has seen a wide range of diseases resulting from zoonotic infections, of which bacterial infections have led to outbreaks of food-borne diseases.

AIM

The study looks at bacterial pathogen carriage by farm rats and their antimicrobial susceptibility, with the view of providing insights for antimicrobial surveillance.

METHOD

Farm rats of Rattus rattus species where randomly collected alive from farms in Al-Ahsa using food baits. They were anaesthetize with urethane within 4 h of collection and were unconscious for the collection of samples. Basic bacteriological culturing methods were used for culturing of bacterial isolates on selective media while the Vitek 2 compact automated system (BioMerieux, Marcy L'Etoile, France) was used for bacteria identification and antimicrobial susceptibility test. Obtained data were analysed using chi-square and paired t-test with significant difference between sensitive and resistance to antimicrobial susceptibility taken at P < .05.

RESULTS

Isolated Gramme-negative pathogenic bacteria included strains of Escherichia coli, Pseudomonas oryzihabitans, strains of Pseudomonas aeruginosa, and Salmonella. For the Gramme-positive bacteria, 4 strains of Staphylococcus aureus were encountered. Other Gramme-positive bacteria were coagulase-negative Staphylococcal species (CoNS) as well as Staphylococcus lugdunensis. There was a 100% resistance to the penicillins and a high resistance to imipenem (71%) by the Staphylococcal isolates. Resistance was also high against the β-lactams by the Gramme-positive bacteria isolates. For the Gramme-negative bacteria, there was a higher than 50% resistance by the isolates against the following antibiotics: ampicillin (78%), amoxicillin/clavulanic acid (67%), cefotaxime (77%), ceftazidime (67%), cefepime (78%), norfloxacin (67%), nitrofurantoin (67%), and trimethoprim/sulfamethoxazole (78%).

CONCLUSION

The results showed high antimicrobial resistance that will need monitoring for control of spread from farm rats to humans.

Sex and age distributions of persons in foodborne disease outbreaks and associations with food categories

Sex and age differences in food preferences may be reflected in the demographics of outbreaks. Outbreaks from 1998-2015 with a single confirmed implicated food source in the Centers for Disease Control and Prevention Foodborne Disease Outbreak Surveillance System were analysed using logistic regression to assess associations between a food category, sex and age. Males were more likely to be involved in outbreaks attributed to beef, pork, game, dairy and shellfish; females were more likely to be involved in grains-beans, nuts-seeds, fruits, sprouts and vegetable row crops outbreaks. Children &lt;5-years-old were more likely than other age groups to be involved in dairy outbreaks, children 5-19-years-old were most likely to be involved in beef and game outbreaks, adults 20-49-years-old were most likely to be involved in fish, shellfish and sprout outbreaks and adults ⩾50-years-old were most likely to be involved in turkey outbreaks. Age and sex are associated with specific food categories in outbreaks. This information may be useful in helping to identify sources of foodborne disease outbreaks.

Safety of ready-to-eat chicken in Burkina Faso: Microbiological quality, antibiotic resistance, and virulence genes in Escherichia coli isolated from chicken samples of Ouagadougou

In Burkina Faso, flamed/grilled chickens are very popular and well known to consumers. The aim of this study was to evaluate the microbiological quality, the antibiotic resistance, and the virulence gene from Escherichia coli isolated from these chickens in Ouagadougou. A total of 102 grilled, flamed, and fumed chickens were collected in Ouagadougou and analyzed, using standard microbiological methods. All E. coli isolates were checked with the antimicrobial test and also typed by 16‐plex PCR. The mean of aerobic mesophilic bacteria (AMB) and thermo‐tolerant coliforms (TTC) was found respectively between 6.90 ± 0.12 × 10⁷CFU/g to 2.76 ± 0.44 × 10⁸CFU/g and 2.4 ± 0.82 × 10⁷CFU/g to 1.27 ± 0.9 × 10⁸CFU/g. E. coli strains were found to 27.45%. Forty samples (38.24%) were unacceptable based on the AMB load. Fifty‐nine samples (57.85%) were contaminated with TTCs. Low resistance was observed with antibiotics of betalactamin family. Diarrheagenic E. coli strains were detected in 21.43% of all samples. This study showed that flamed/grilled chickens sold in Ouagadougou could pose health risks for the consumers. Need of hygienic practices or system and good manufacturing practices is necessary to improve the hygienic quality of flamed/grilled chickens. Our results highlight the need of control of good hygiene and production practices to contribute to the improvement of the safety of the products and also to avoid antibiotic resistance. Slaughter, scalding, evisceration, plucking, bleeding, washing, rinsing, preserving, grilling, and selling may be the ways of contamination.

An outbreak of Escherichia coli O157:H7 infections following a dairy education school field trip in Washington state, 2015

On 27 April 2015, Washington health authorities identified Escherichia coli O157:H7 infections associated with dairy education school field trips held in a barn 20-24 April. Investigation objectives were to determine the magnitude of the outbreak, identify the source of infection, prevent secondary illness transmission and develop recommendations to prevent future outbreaks. Case-finding, hypothesis generating interviews, environmental site visits and a case-control study were conducted. Parents and children were interviewed regarding event activities. Odds ratios (OR) and 95% confidence intervals (CI) were computed. Environmental testing was conducted in the barn; isolates were compared to patient isolates using pulsed-field gel electrophoresis (PFGE). Sixty people were ill, 11 (18%) were hospitalised and six (10%) developed haemolytic uremic syndrome. Ill people ranged in age from <1 year to 47 years (median: 7), and 20 (33%) were female. Twenty-seven case-patients and 88 controls were enrolled in the case-control study. Among first-grade students, handwashing (i.e. soap and water, or hand sanitiser) before lunch was protective (adjusted OR 0.13; 95% CI 0.02-0.88, P = 0.04). Barn samples yielded E. coli O157:H7 with PFGE patterns indistinguishable from patient isolates. This investigation provided epidemiological, laboratory and environmental evidence for a large outbreak of E. coli O157:H7 infections from exposure to a contaminated barn. The investigation highlights the often overlooked risk of infection through exposure to animal environments as well as the importance of handwashing for disease prevention. Increased education and encouragement of infection prevention measures, such as handwashing, can prevent illness.

Diseases Transmitted by Domestic Livestock: Perils of the Petting Zoo

Petting zoo venues encourage or permit public contact with animals which provide opportunities for education and entertainment. These venues vary but are common at county or state fairs, zoos, and aquariums. In addition to these common petting zoo settings, animals are present in many other venues where the public is permitted to contact them and their environment. Thus, humans may have contact with animals in a wide range of settings, and transmission of infectious diseases from animals to humans may occur at any of these venues, creating perils associated with petting zoos.There are many considerations when evaluating perils associated with the wide range of venues where animal contact can occur. First, many venues or events draw large numbers of people; some operate during a short time frame, while others, such as zoos and aquariums, operate year round. Second, petting zoos and other animal contact venues are particularly popular with children, who compared with adults, commonly have less stringent hygienic practices and are more susceptible to severe disease outcomes. Finally, there is remarkable variability in the physical layout of venues that permit animal contact and in the types of animals that may be contacted. Animal contact areas range from well-designed permanent exhibits targeting risk reduction to various temporary or seasonal exhibits established without detailed planning. Many petting zoos house only small ruminant species such as sheep and goats, but other venues house a wide variety of mammalian species, exotic animals, poultry and other avian species, reptiles and amphibians, and aquatic animals.

Real-time genomic investigation underlying the public health response to a Shiga toxin-producing Escherichia coli O26:H11 outbreak in a nursery

Shiga toxin-producing Escherichia coli (STEC) is a significant cause of gastrointestinal infection and the haemolytic-uremic syndrome (HUS). STEC outbreaks are commonly associated with food but animal contact is increasingly being implicated in its transmission. We report an outbreak of STEC affecting young infants at a nursery in a rural community (three HUS cases, one definite case, one probable case, three possible cases and five carriers, based on the combination of clinical, epidemiological and laboratory data) identified using culture-based and molecular techniques. The investigation identified repeated animal contact (animal farming and petting) as a likely source of STEC introduction followed by horizontal transmission. Whole genome sequencing (WGS) was used for real-time investigation of the incident and revealed a unique strain of STEC O26:H11 carrying stx2a and intimin. Following a public health intervention, no additional cases have occurred. This is the first STEC outbreak reported from Israel. WGS proved as a useful tool for rapid laboratory characterization and typing of the outbreak strain and informed the public health response at an early stage of this unusual outbreak.

Animal-related factors associated with moderate-to-severe diarrhea in children younger than five years in western Kenya: A matched case-control study

BACKGROUND

Diarrheal disease remains among the leading causes of global mortality in children younger than 5 years. Exposure to domestic animals may be a risk factor for diarrheal disease. The objectives of this study were to identify animal-related exposures associated with cases of moderate-to-severe diarrhea (MSD) in children in rural western Kenya, and to identify the major zoonotic enteric pathogens present in domestic animals residing in the homesteads of case and control children.

METHODOLOGY/PRINCIPAL FINDINGS

We characterized animal-related exposures in a subset of case and control children (n = 73 pairs matched on age, sex and location) with reported animal presence at home enrolled in the Global Enteric Multicenter Study in western Kenya, and analysed these for an association with MSD. We identified potentially zoonotic enteric pathogens in pooled fecal specimens collected from domestic animals resident at children's homesteads. Variables that were associated with decreased risk of MSD were washing hands after animal contact (matched odds ratio [MOR] = 0.2; 95% CI 0.08-0.7), and presence of adult sheep that were not confined in a pen overnight (MOR = 0.1; 0.02-0.5). Variables that were associated with increased risk of MSD were increasing number of sheep owned (MOR = 1.2; 1.0-1.5), frequent observation of fresh rodent excreta (feces/urine) outside the house (MOR = 7.5; 1.5-37.2), and participation of the child in providing water to chickens (MOR = 3.8; 1.2-12.2). Of 691 pooled specimens collected from 2,174 domestic animals, 159 pools (23%) tested positive for one or more potentially zoonotic enteric pathogens (Campylobacter jejuni, C. coli, non-typhoidal Salmonella, diarrheagenic E. coli, Giardia, Cryptosporidium, or rotavirus). We did not find any association between the presence of particular pathogens in household animals, and MSD in children.

CONCLUSIONS AND SIGNIFICANCE

Public health agencies should continue to promote frequent hand washing, including after animal contact, to reduce the risk of MSD. Future studies should address specific causal relations of MSD with sheep and chicken husbandry practices, and with the presence of rodents.

Preventing Enteric Infections from Contact with Animals

Precautions when visiting petting zoos and state fairs.

Descriptive study of enteric zoonoses in Ontario, Canada, from 2010 - 2012

BACKGROUND

Contact with animals and their environment has long been recognized as an important source of enteric zoonoses. However, there are limited data available on the burden of illness associated with specific types of animals in Canada. This study describes the overall burden of enteric zoonoses in Ontario, Canada from 2010 to 2012.

METHODS

Confirmed cases of seven enteric zoonotic diseases (campylobacteriosis, cryptosporidiosis, giardiasis, listeriosis, salmonellosis, verotoxin-producing E. coli (VTEC) infection, and yersiniosis) with episode dates from 2010 to 2012 were extracted from the integrated Public Health Information System (iPHIS). Reported exposures were categorized as animal contact, foodborne, waterborne and 'other', with animal contact grouped into nine sub-categories based on the type of animal or transmission setting. Overall incidence rates and proportions by animal exposure categories, age and sex-specific incidence rates and hospitalization and death proportions were calculated and sex proportions compared.

RESULTS

Our study found that approximately 26% of the enteric pathogens assessed during the 2010 to 2012 period reported contact with animals and their environments as the mode of transmission. Of enteric disease cases reporting animal contact, farm exposures were reported for 51.3%, dog or cat exposures for 26.3%, and reptile or amphibian exposures for 8.9%.

CONCLUSIONS

Contact with animals was reported more frequently during the period 2010 to 2012 in comparison to the period 1997 to 2003 when 6% or less of enteric cases were associated with animal contact. Public health professionals, stakeholders associated with animals and their related industries (e.g., pet treats, mobile zoos, abattoirs), and the public should recognize that animal contact is an important source of enteric illnesses in order to take measures to reduce the burden of illness from animal sources.

Disease and Human/Animal Interactions

Understanding pathogen exchange among human, wildlife, and livestock populations, and the varying ecological and cultural contexts in which this exchange takes place, is a major challenge. The present review contextualizes the risk factors that result from human interactions with livestock, companion animals, animal exhibits, wildlife through nature-based tourism, and wildlife through consumption. Given their phylogenetic relatedness to humans, primates are emphasized in this discussion; primates serve as reservoirs for several human pathogens, and some human pathogens can decimate wild primate populations. Anthropologists must play a central role in understanding cultural variation in attitudes toward other species as well as perceived risks when interacting with animals. I argue that the remediation of emerging infectious diseases will be accomplished primarily through human behavioral changes rather than through efforts in pathogen discovery. Given the history of human interactions with wildlife, candid discussions on zoonotic diseases will be increasingly important for our combined survival.

An outbreak of Shiga toxin-producing Escherichia coli serogroup O157 linked to a lamb-feeding event

Fifteen confirmed cases and 15 possible cases of Shiga toxin-producing Escherichia coli (STEC) O157 phage type 21/28 were linked to direct contact with lambs at a 'Lambing Live' event in the North West of England between 29 March and 21 April 2014. Twenty-one (70%) of the cases were female, 23 (77%) were children aged <16 years, of whom 14 (46%) were in the 0-5 years age group. Five children developed haemolytic uraemic syndrome. Multilocus variable number tandem repeat analysis (MLVA) profiles on 14 human cases were indistinguishable, and 6/10 animal isolates had a MLVA profile identical to the outbreak profile. Whole-genome sequencing analysis revealed that all isolates, both human and animal, fell within a 5-single nucleotide polymorphism cluster indicating the isolates belonged to the same point source. On inspection of the premises, extensive and uncontrolled physical contact between visitors and animals was occuring within the animal pens and during bottle-feeding. Public areas were visibly contaminated with animal faeces. Information to visitors, and the infection control awareness demonstrated by staff, was inadequate. Managing the risk to visitors of STEC O157 infection at animal petting events and open farms requires implementation of stringent control measures by the operator, as outlined in the industry code of practice. Enforcement action is sometimes required to prevent high-risk activities taking place at both permanent and temporary attractions.

Perceptions of Health and Safety among Immigrant Latino/a Dairy Workers in the U.S

The U.S. dairy industry is increasingly relying on an immigrant workforce to help meet growing demands. Due to scant research, little is known about the factors related to workplace safety among this occupational group. The purpose of this study was to identify dairy worker perceptions of the barriers to and facilitators for enhancing workplace safety. Focus groups (FG) were conducted with 44 immigrant Latino/a workers from 2 dairies in South Dakota and 1 dairy in Colorado to gain firsthand insights into their work experiences. Interviews were conducted in Spanish, audio recorded, transcribed, and translated into English. Results were analyzed through a two-step qualitative coding process. The Contributing Factors in Accident Causation model was used as a guiding framework. Promising points of intervention identified were related to the workers, the work itself, the physical environment, equipment issues, the social-psychological environment, and management/organizational factors. Suggestions for how to improve safety outcomes in the dairy industry are provided. It is likely that the dairy industry will continue to employ a growing number of immigrant workers. Therefore, these findings have significant implications that can be used to guide the development of culturally congruent policies and practices.

The Two-Component System CpxRA Negatively Regulates the Locus of Enterocyte Effacement of Enterohemorrhagic Escherichia coli Involving σ(32) and Lon protease

Enterohemorrhagic Escherichia coli (EHEC) is a significant cause of serious human gastrointestinal disease worldwide. EHEC strains contain a pathogenicity island called the locus of enterocyte effacement (LEE), which encodes virulence factors responsible for damaging the gut mucosa. The Cpx envelope stress response of E. coli is controlled by a two-component system (TCS) consisting of a sensor histidine kinase (CpxA) and a cytoplasmic response regulator (CpxR). In this study, we investigated the role of CpxRA in the expression of LEE-encoded virulence factors of EHEC. We found that a mutation in cpxA significantly affected adherence of EHEC to human epithelial cells. Analysis of this mutant revealed the presence of high levels of CpxR which repressed transcription of grlA and ler, the main positive virulence regulators of the LEE, and influenced negatively the production of the type 3 secretion system–associated EspABD translocator proteins. It is known that CpxR activates rpoH (Sigma factor 32), which in turns activates transcription of the lon protease gene. We found that transcription levels of ler and grlA were significantly increased in the lon and cpxA lon mutants suggesting that lon is involved in down-regulating LEE genes. In addition, the Galleria mellonella model of infection was used to analyze the effect of the loss of the cpx and lon genes in EHEC's ability to kill the larvae. We found that the cpxA mutant was significantly deficient at killing the larvae however, the cpxA lon mutant which overexpresses LEE genes in vitro, was unable to kill the larvae, suggesting that virulence in the G. mellonella model is T3SS independent and that CpxA modulates virulence through a yet unknown EHEC-specific factor. Our data provides new insights and broadens our scope into the complex regulatory network of the LEE in which the CpxA sensor kinase plays an important role in a cascade involving both global and virulence regulators.

A Systematic Review and Meta-Analysis of the Campylobacter spp. Prevalence and Concentration in Household Pets and Petting Zoo Animals for Use in Exposure Assessments

Animal contact is a potential transmission route for campylobacteriosis, and both domestic household pet and petting zoo exposures have been identified as potential sources of exposure. Research has typically focussed on the prevalence, concentration, and transmission of zoonoses from farm animals to humans, yet there are gaps in our understanding of these factors among animals in contact with the public who don't live on or visit farms. This study aims to quantify, through a systematic review and meta-analysis, the prevalence and concentration of Campylobacter carriage in household pets and petting zoo animals. Four databases were accessed for the systematic review (PubMed, CAB direct, ProQuest, and Web of Science) for papers published in English from 1992-2012, and studies were included if they examined the animal population of interest, assessed prevalence or concentration with fecal, hair coat, oral, or urine exposure routes (although only articles that examined fecal routes were found), and if the research was based in Canada, USA, Europe, Australia, and New Zealand. Studies were reviewed for qualitative synthesis and meta-analysis by two reviewers, compiled into a database, and relevant studies were used to create a weighted mean prevalence value. There were insufficient data to run a meta-analysis of concentration values, a noted study limitation. The mean prevalence of Campylobacter in petting zoo animals is 6.5% based on 7 studies, and in household pets the mean is 24.7% based on 34 studies. Our estimated concentration values were: 7.65x103cfu/g for petting zoo animals, and 2.9x105cfu/g for household pets. These results indicate that Campylobacter prevalence and concentration are lower in petting zoo animals compared with household pets and that both of these animal sources have a lower prevalence compared with farm animals that do not come into contact with the public. There is a lack of studies on Campylobacter in petting zoos and/or fair animals in Canada and abroad. Within this literature, knowledge gaps were identified, and include: a lack of concentration data reported in the literature for Campylobacter spp. in animal feces, a distinction between ill and diarrheic pets in the reported studies, noted differences in shedding and concentrations for various subtypes of Campylobacter, and consistent reporting between studies.

Shiga Toxin Producing Escherichia coli

Shiga toxin-producing Escherichia coli (STEC) is among the common causes of foodborne gastroenteritis. STEC is defined by the production of specific toxins, but within this pathotype there is a diverse group of organisms. This diversity has important consequences for understanding the pathogenesis of the organism, as well as for selecting the optimum strategy for diagnostic testing in the clinical laboratory. This review includes discussions of the mechanisms of pathogenesis, the range of manifestations of infection, and the several different methods of laboratory detection of Shiga toxin-producing E coli.

Characterization of Shiga toxin-producing Escherichia coli isolated from ground beef collected in different socioeconomic strata markets in Buenos Aires, Argentina

Consumption of raw/undercooked ground beef is the most common route of transmission of Shiga toxin-producing E. coli (STEC). The aim of the study was to determine the STEC contamination level of the ground beef samples collected in 36 markets of different socioeconomic strata in Buenos Aires, Argentina, and the characterization of the isolated strains. Ninety-one out of 252 (36.1%) samples were stx+. Fifty-seven STEC strains were recovered. Eleven STEC strains belonged to O157 serogroup, and 46 to non-O157 serogroups. Virulence markers of the 57 STEC were stx1, 5.3% (3/57); stx2, 86.0% (49/57); stx1/stx2, 8.8% (5/57); ehxA, 61.4% (35/57); eae, 26.3% (15/57); saa, 24.6% (14/57). Shiga toxin subtypes were stx2, 31.5% (17/54); stx2c-vhb, 24.1% (13/54); stx2c-vha, 20.4% (11/54); stx2/stx2c-vha, 14.8% (8/54); stx2/stx2c-vhb, 5.6% (3/54); stx2c-vha/vhb, 3.7% (2/54). Serotypes O178:H19 and O157:H7 were prevalent. Contamination rate of STEC in all strata was high, and the highest O157 contamination was observed at low strata at several sampling rounds. Persistence of STEC was not detected. Sixteen strains (28.1%) were resistant to ampicillin, streptomycin, amikacin, or tetracycline. The STEC contamination level of ground beef could vary according to the sociocultural characteristics of the population.

Occurrence and characterization of Shiga toxin-producing Escherichia coli O157:H7 and other non-sorbitol-fermenting E. coli in cattle and humans in urban areas of Morogoro, Tanzania

Escherichia coli strains such as Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli, enterotoxigenic, attaching, and effacing E. coli, and enteroinvasive E. coli cause diarrhea in humans. Although other serotypes exist, the most commonly reported STEC in outbreaks is O157:H7. A cross-sectional study was conducted to isolate and characterize non-sorbitol-fermenting (NSF) E. coli O157:H7 from urban and periurban livestock settings of Morogoro, Tanzania. Human stool, cattle feces, and soil and water samples were collected. Observations and questionnaire interview studies were used to gather information about cattle and manure management practices in the study area. E. coli were isolated on sorbitol MacConkey agar and characterized by conventional biochemical tests. Out of 1049 samples, 143 (13.7%) yielded NSF E. coli. Serological and antimicrobial tests and molecular typing were performed to NSF E. coli isolates. These procedures detected 10 (7%) pathogenic E. coli including STEC (n=7), enteropathogenic E. coli (EPEC) (n=2), and attaching and effacing E. coli (A/EEC) (n=1) strains. The STEC strains had the ability to produce VT1 and different VT2 toxin subtypes that caused cytopathic effects on Vero cells. The prevalence of STEC in cattle was 1.6%, out of which 0.9% was serotype O157:H7 and the overall prevalence of diarrheagenic E. coli in cattle was 2.2%. The serotypes O157:H7, O142:H34, O113:H21, O+:H-, O+:H16, and O25:H4 were identified. One ESBL-producing isolate showed the MLST type ST131. To our knowledge, this is the first finding in Tanzania of this recently emerged worldwide pandemic clonal group, causing widespread antimicrobial-resistant infections, and adds knowledge of the geographical distribution of ST131. Cattle manure was indiscriminately deposited within residential areas, and there was direct contact between humans and cattle feces during manure handling. Cattle and manure management practices expose humans, animals, and the environment to pathogenic E. coli and other manure-borne pathogens. Therefore, there is a need to improve manure management practices in urban and periurban areas to prevent pathogen spread and associated human health risks.

Transmission of Escherichia coli O157:H7 in cattle is influenced by the level of environmental contamination

A pen infection-transmission experiment was conducted to elucidate the role of pathogen strain and environmental contamination in transmission of Escherichia coli O157:H7 (ECO157) in cattle. Five steers were inoculated with a three-strain mixture of ECO157 and joined with five susceptible steers in each of two experimental replicates. Faecal and environmental samples were monitored for ECO157 presence over 30 days. One ECO157 strain did not spread. Transmission rates for the other two strains were estimated using a generalized linear model developed based on a modified ‘Susceptible–Infectious–Susceptible’ mathematical model. Transmission rates estimated for the two strains (0·11 and 0·14) were similar. However, the rates significantly (P = 0·0006) increased 1·5 times for every 1-unit increase in the level of environmental contamination measured as log₁₀ c.f.u. Depending on the level of environmental contamination, the estimated basic reproduction numbers varied from <1 to 8. The findings indicate the importance of on-farm measures to reduce environmental contamination for ECO157 control in cattle that should be validated under field conditions.

Impedance based detection of pathogenic E. coli O157:H7 using a ferrocene-antimicrobial peptide modified biosensor

Escherichia coli O157:H7 can cause life-threatening gastrointestinal diseases and has been a severe public health problem worldwide in recent years. A novel biosensor for the detection of E. coli O157:H7 is described here using a film composed of ferrocene-peptide conjugates, in which the antimicrobial peptide magainin I has been incorporated as the biorecognition element. Electrochemical impedance spectroscopy was employed to investigate the surface characteristics of the newly developed biosensor and to monitor the interactions between the peptide film and the pathogenic bacteria. X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were employed to confirm the immobilization of ferrocene-conjugate onto the gold surface. Non-pathogenic E. coli K12, Staphylococcus epidermidis and Bacillus subtilis were used in this study to evaluate the selectivity of the proposed biosensor. The results have shown the order of the preferential selectivity of the method is E. coli O157:H7>non-pathogenic E. coli>gram positive species. The detection of E. coli O157:H7 with a sensitivity of 10(3)cfu/mL is enabled by the biosensor. The experimental conditions have been optimized and the plot of changes of charge transfer resistance (ΔRCT) and the logarithm of the cell concentration of E. coli O157:H7 shows a linear correlation in the range of 10(3)-10(7)cfu/mL with a correlation coefficient of 0.983.

Hemolytic uremic syndrome

Hemolytic uremic syndrome (HUS) is a thrombotic microangiopathy defined by thrombocytopenia, nonimmune microangiopathic hemolytic anemia, and acute renal failure. The most frequent form is associated with infections by Shiga-like toxin-producing bacteria (STEC-HUS). Rarer cases are triggered by neuraminidase-producing Streptococcus pneumoniae (pneumococcal-HUS). The designation of aHUS is used to refer to those cases in which an infection by Shiga-like toxin-producing bacteria or S. pneumoniae can be excluded. Studies performed in the last two decades have documented that hyperactivation of the complement system is the pathogenetic effector mechanism leading to the endothelial damage and the microvascular thrombosis in aHUS. Recent data suggested the involvement of the complement system in the pathogenesis of STEC-HUS and pneumococcal-HUS as well. Clinical signs and symptoms may overlap among the different forms of HUS; however, pneumococcal-HUS and aHUS have a worse prognosis compared with STEC-HUS. Early diagnosis and identification of underlying pathogenetic mechanism allows instating specific support measures and therapies. In clinical trials in patients with aHUS, complement inhibition by eculizumab administration leads to a rapid and sustained normalization of hematological parameters with improvement in long-term renal function. This review summarizes current concepts about the epidemiological findings, the pathological and clinical aspects of STEC-HUS, pneumococcal-HUS, and aHUS, and their diagnosis and management.

Interventions for preventing diarrhea-associated hemolytic uremic syndrome: systematic review

BACKGROUND

Hemolytic Uremic Syndrome (HUS) may follow infection with Shiga-toxin-producing organisms, principally E. coli O157: H7 (STEC), causing high morbidity and mortality. Our aim was to identify interventions to prevent diarrhea-associated HUS.

METHODS

Systematic search of the literature for relevant systematic reviews (SRs), randomised controlled trials (RCTs) and public health guidelines.

RESULTS

Of 1097 animal and 762 human studies, 18 animal studies (2 SRs, 2 reviews, plus 14 RCTs) and 6 human studies (3 SRs, plus 3 RCTs) met inclusion criteria. E. coli O157: H7 Type III secreted protein vaccination decreased fecal E. coli O157 shedding in cattle (P = 0.002). E. coli O157: H7 siderophore receptor and porin proteins (SRP) vaccines reduced fecal shedding in cows (OR 0.42 (95% CI 0.25 to 0.73) and increased anti-E. coli 0157: H7 SRP antibodies in their calves (P < 0.001). Bacterin vaccines had no effect. Probiotic or sodium chlorate additives in feeds reduced fecal E. coli O157 load as did improved farm hygiene (P < 0.05). Solarization of soil reduced E. coli O157: H7 contamination in the soil (P < 0.05). In an RCT examining the role of antibiotic treatment of E. coli O157: H7 diarrhea, HUS rates were similar in children treated with Trimethoprim-sulfamethoxazole and controls (RR 0.57; 95% CI 0.11 to 2.81). In another RCT, HUS rates were similar in children receiving Synsorb-Pk and placebo (RR 0.93; 95% CI 0.39 to 2.22). In one SR, hand washing reduced diarrhea by 39% in institutions (IRR 0.61; 95% CI 0.40 to 0.92) and 32% in community settings (IRR 0.68; 95% CI 0.52 to 0.90) compared to controls. Guidelines contained recommendations to prevent STEC transmission from animals and environments to humans, including appropriate food preparation, personal hygiene, community education, and control of environmental contamination, food and water quality.

CONCLUSIONS

Animal carriage of STEC is decreased by vaccination and improved farm practices. Treatment of STEC diarrhea with antibiotics and toxin-binders did not prevent HUS. Public health interventions are the key to preventing STEC-associated diarrhea and HUS.

Food safety in home kitchens: a synthesis of the literature

Although foodborne illness is preventable, more than 56,000 people per year become ill in the U.S., creating high economic costs, loss of productivity and reduced quality of life for many. Experts agree that the home is the primary location where foodborne outbreaks occur; however, many consumers do not believe the home to be a risky place. Health care professionals need to be aware of consumers' food safety attitudes and behaviors in the home and deliver tailored food safety interventions that are theory-based. Thus, the purpose of this paper is to synthesize/summarize the food safety literature by examining the following: consumers' perceptions and attitudes towards food safety and their susceptibility to foodborne illness in the home, work, and school; common risky food safety practices and barriers to handling food safely; and the application of theory-based food safety interventions. Findings will help healthcare professionals become more aware of consumers' food safety attitudes and behaviors and serve to inform future food safety interventions.

Comparison between ImmunoCard STAT!(®) and real-time PCR as screening tools for both O157:H7 and non-O157 Shiga toxin-producing Escherichia coli in Southern Alberta, Canada

An increasing number of non-O157 Shiga toxin-producing Escherichia coli (STEC) infections and outbreaks have been reported. In this study, we evaluated the performance of ImmunoCard STAT!(®) (Meridian Bioscience, Inc., Cincinnati, OH, USA) as a method to screen stool specimens for STEC (O157 and non-O157). An in-house real-time PCR method was used as the "gold standard". We also evaluated the prevalence and clinical characteristics of STEC infections in the Alberta South West Zone. From July to November 2011, 819 stool specimens submitted for routine stool culture were tested. With our in-house real-time PCR, 7 O157:H7 and 10 non-O157 STEC isolates were identified for a total of 17 STECs. In comparison, ImmunoCard STAT!(®) identified a total of 6, resulting in a sensitivity and specificity of 35% and 99%, respectively (P < 0.05). Because of the low sensitivity, ImmunoCard STAT!(®) cannot be recommended as a routine screening test for STEC from enriched stool specimens. The rate of STEC positivity as detected by PCR was 2.08%, of which 0.86% was O157:H7 and 1.22% non-O157 STEC. Five of the 7 cases of STEC O157 infection experienced bloody diarrhea, and 1 developed hemolytic uremic syndrome.

Molecular and antimicrobial susceptibility analyses distinguish clinical from bovine Escherichia coli O157 strains

A population-based study combining (i) antimicrobial, (ii) genetic, and (iii) virulence analyses with molecular evolutionary analyses revealed segregative characteristics distinguishing human clinical and bovine Escherichia coli O157 strains from western Canada. Human (n = 50) and bovine (n = 50) strains of E. coli O157 were collected from Saskatchewan and Manitoba in 2006 and were analyzed by using the six-marker lineage-specific polymorphism assay (LSPA6), antimicrobial susceptibility analysis, the colicin assay, plasmid and virulence profiling including the eae, ehxA, espA, iha, stx1, stx2, stx2c, stx2d, stx2d-activatable, stx2e, and stx2f virulence-associated genes, and structure analyses. Multivariate logistic regression and Fisher's exact test strongly suggested that antimicrobial susceptibility was the most distinctive characteristic (P = 0.00487) associated with human strains. Among all genetic, virulence, and antimicrobial determinants, resistance to tetracycline (P < 0.000) and to sulfisoxazole (P < 0.009) were the most strongly associated segregative characteristics of bovine E. coli O157 strains. Among 11 virulence-associated genes, stx2c showed the strongest association with E. coli O157 strains of bovine origin. LSPA6 genotyping showed the dominance of the lineage I genotype among clinical (90%) and bovine (70%) strains, indicating the importance of lineage I in O157 epidemiology and ecology. Population structure analysis revealed that the more-diverse bovine strains came from a unique group of strains characterized by a high degree of antimicrobial resistance and high frequencies of lineage II genotypes and stx2c variants. These findings imply that antimicrobial resistance generated among bovine strains of E. coli O157 has a large impact on the population of this human pathogen.

Virulence Genes in Isolates of Escherichia coli from Samples of Milk and Feces from Dairy Cattle

The aim of this work was to determine if Escherichia coli isolates carrying the virulence genes eae and eltB and exhibiting the Ehly phenotype are present in feces and milk samples from healthy dairy cattle on farms. Isolates from calves showed a statistically higher prevalence of eae and eltB compared with isolates from older animals. The other factors tested (stx1, stx2, and Ehly) were not statistically different between the two groups. Two isolates originating from calf feces were identified as serotype O157:H7; one of these isolates carried stx1 and eae, the other stx2 and eae. E. coli isolated from milk contained stx1, stx2, and eltB. The results show that feces or milk from healthy dairy cattle may contain E. coli pathotypes that express virulence genes, indicating that these materials have zoonotic potential. The results also reinforce the idea that host age can influence the dynamics of virulence genes in E. coli from cattle.

A population-based exposure assessment of risk factors associated with gastrointestinal pathogens: a Campylobacter study

A questionnaire survey was undertaken to determine the exposure of a study population to campylobacteriosis source risk factors (environmental, water, food) and results were stratified by age, population density and deprivation. Data were gathered using an exposure assessment carried out by telephone in the Grampian region of Scotland. Univariate analysis showed that children aged 5-14 years, living in low population density (0-44.4 persons/km2) and affluent areas had elevated exposure to environmental and water risk factors. Multivariate logistic regression analysis revealed that younger age groups and lower population density were significant indicators for most environmental risk factors. The results compared to reported disease incidence in Grampian showed that greater exposure to risk factors does not necessarily coincide with greater disease incidence for age groups, particularly for the 0-4 years age group. Further research is required to explain the relationship between exposure and disease incidence.

The impact of community-based, workshop activities in multiple local dialects on the vaccination coverage, sanitary living and the health status of multiethnic populations in Lao PDR

Studies on effective community-based intervention in areas inhabited by multiple ethnic groups are limited. The present study was performed to evaluate the impact of workshop activities in multiple local dialects guided by lay facilitators on vaccination coverage, sanitary living and health status in a northern district of Lao PDR. In target villages, facilitators were selected and trained to assist at village meetings to discuss health issues and develop and implement action plans. Manuals and posters with graphics were distributed. Skills were taught through demonstrations by specialists. The vaccination coverage among children and women improved significantly after 1 year. Villagers started using toilets, collecting and burning garbage, and isolating animals from human dwellings, and these activities were continued in 76, 84 and 87% of villages, respectively, 5 years after the start of the activities. The frequency of villagers falling ill was reduced in 67% of the villages. After adjustment for sociocultural characteristics and ethnicity, both the continuous sanitary living index and the reduction in the frequency of villagers falling ill were associated with the higher levels of community participation in the workshop activities. The results demonstrated that the community-based workshop activities improved vaccination coverage, sanitary living and health status. Participatory group discussions in local dialects and village activities led by lay facilitators, supervision and consultation by district trainers who were well recognized by villagers, and the distribution of pictorial educational materials can be an effective and sustainable health promotion approaches among multiethnic groups in under-resourced areas.

Escherichia coli O157:H7 Outbreak Linked to Raw Milk Cheese in Quebec, Canada: Use of Exact Probability Calculation and Case-Case Study Approaches to Foodborne Outbreak Investigation

The analytical studies used to investigate foodborne outbreak are mostly case-control or retrospective cohort studies. However, these studies can be complex to perform and susceptible to biases. This article addresses basic principles of epidemiology, probability, and the use of case-case design to identify the source of an Escherichia coli O157:H7 outbreak linked to raw milk cheese consumption in Quebec, Canada; a small number of cases with the same pulsed-field gel electrophoresis (PFGE) profile were involved. Between 4 December 2008 and 15 January 2009, a cumulative total of 16 E. coli O157:H7 cases with the same PFGE profile were reported to Quebec public health authorities. Among the first six cases reported, three had consumed raw milk cheese from the same producer (cheese A). Raw milk cheese is consumed by about 2% of the Quebec population. By using the exact probability calculation, it was found that a significantly higher proportion of E. coli O157:H7 cases (with the specific PFGE profile) than expected had consumed cheese A (P &lt; 0.001). These computations were updated during the course of the investigation to include subsequent cases and gave the same results. A case-case study corroborated this result. This article considers alternative statistical and epidemiological approaches to investigate a foodborne outbreak—in particular with an exact probability calculation and case-case comparisons. This approach could offer a fast and inexpensive alternative to regular case-control studies to target public health actions, particularly during a foodborne outbreak.

Study Prevalence of Verotoxigenic E.coli Isolated from Urinary Tract Infections (UTIs) in an Iranian Children Hospital

BACKGROUND AND OBJECTIVES

Urinary tract infections (UTI) caused by enterohemorrhagic Escherichia coli (EHEC) is one of the most important diseases in infants and children. If there would not be any useful diagnosis and treatment it may be resulted in diseases such as acute renal failure, thrombocytopenia and hemolytic anemia. The aim of this study was to determine frequency of verotoxigenic E.coli isolates in urine of children with (UTIs) in Mofid children Hospital.

METHODS

During one year from September 2008 to august 2009, urine specimens were taken from children who suspected to UTI admitted to Mofid Children Hospital. E.coli strains that indicated beta hemolytic on sheep blood agar, negative sorbitol fermentation on SMAC (sorbitol macconky agar) and negative motility on SIM were tested by PCR and serologic (VITEC-RPLA kit) methods for detecting toxin genes and production of toxin, respectively.

RESULTS

Among 12572 urine specimens were taken from children admitted to Mofid hospital, we isolated 378 E.coli from urine samples which only 9 isolates were EHEC. Only five EHEC strains (55%) which produced vtx genes, were detected by serologic and PCR methods.

CONCLUSION

The prevalence of urinary infections caused by EHEC strains is very significant because it causes aggravating pathologic effects. Thus we suggest rapid method for identification of this bacteria and proper treatment to Inhibition of unwanted complications.

The strain-specific dynamics of Escherichia coli O157:H7 faecal shedding in cattle post inoculation

This study reports analysis of faecal shedding dynamics in cattle for three Escherichia coli O157:H7 (ECO157) strains (S1, S2 and S3) of different genotype and ecological history, using experimental inoculation data. The three strains were compared for their shedding frequency and level of ECO157 in faeces. A multistate Markov chain model was used to compare shedding patterns of S1 and S2. Strains S1 and S2 were detected seven to eight times more often and at 10(4) larger levels than strain S3. Strains S1 and S2 had similar frequencies and levels of shedding. However, the total time spent in the shedding state during colonization was on average four times longer for S1 (15 days) compared to S2 (4 days). These results indicate that an ECO157 strain effect on the frequency, level, pattern and the duration of faecal shedding may need to be considered in control of ECO157 in the cattle reservoir.

Large outbreak of verocytotoxin-producing Escherichia coli O157 infection in visitors to a petting farm in South East England, 2009

In the summer of 2009, an outbreak of verocytotoxigenic Escherichia coli O157 (VTEC O157) was identified in visitors to a large petting farm in South East England. The peak attack rate was 6/1000 visitors, and highest in those aged <2 years (16/1000). We conducted a case-control study with associated microbiological investigations, on human, animal and environmental samples. We identified 93 cases; 65 primary, 13 secondary and 15 asymptomatic. Cases were more likely to have visited a specific barn, stayed for prolonged periods and be infrequent farm visitors. The causative organism was identified as VTEC O157 PT21/28 with the same VNTR profile as that isolated in faecal specimens from farm animals and the physical environment, mostly in the same barn. Contact with farm livestock, especially ruminants, should be urgently reviewed at the earliest suspicion of a farm-related VTEC O157 outbreak and appropriate risk management procedures implemented without delay.

Foodborne illness acquired in the United States--major pathogens

Estimates of foodborne illness can be used to direct food safety policy and interventions. We used data from active and passive surveillance and other sources to estimate that each year 31 major pathogens acquired in the United States caused 9.4 million episodes of foodborne illness (90% credible interval [CrI] 6.6-12.7 million), 55,961 hospitalizations (90% CrI 39,534-75,741), and 1,351 deaths (90% CrI 712-2,268). Most (58%) illnesses were caused by norovirus, followed by nontyphoidal Salmonella spp. (11%), Clostridium perfringens (10%), and Campylobacter spp. (9%). Leading causes of hospitalization were nontyphoidal Salmonella spp. (35%), norovirus (26%), Campylobacter spp. (15%), and Toxoplasma gondii (8%). Leading causes of death were nontyphoidal Salmonella spp. (28%), T. gondii (24%), Listeria monocytogenes (19%), and norovirus (11%). These estimates cannot be compared with prior (1999) estimates to assess trends because different methods were used. Additional data and more refined methods can improve future estimates.

Foodborne illness acquired in the United States--major pathogens

Each year, 31 pathogens caused 9.4 million episodes of foodborne illness, resulting in 55,961 hospitalizations and 1,351 deaths.

Estimates of foodborne illness can be used to direct food safety policy and interventions. We used data from active and passive surveillance and other sources to estimate that each year 31 major pathogens acquired in the United States caused 9.4 million episodes of foodborne illness (90% credible interval [CrI] 6.6–12.7 million), 55,961 hospitalizations (90% CrI 39,534–75,741), and 1,351 deaths (90% CrI 712–2,268). Most (58%) illnesses were caused by norovirus, followed by nontyphoidal Salmonella spp. (11%), Clostridium perfringens (10%), and Campylobacter spp. (9%). Leading causes of hospitalization were nontyphoidal Salmonella spp. (35%), norovirus (26%), Campylobacter spp. (15%), and Toxoplasmagondii (8%). Leading causes of death were nontyphoidal Salmonella spp. (28%), T.gondii (24%), Listeriamonocytogenes (19%), and norovirus (11%). These estimates cannot be compared with prior (1999) estimates to assess trends because different methods were used. Additional data and more refined methods can improve future estimates.

Video observation of hand hygiene practices at a petting zoo and the impact of hand hygiene interventions

Petting zoos are popular attractions, but can also be associated with zoonotic disease outbreaks. Hand hygiene is critical to reducing disease risks; however, compliance can be poor. Video observation of petting zoo visitors was used to assess animal and environmental contact and hand hygiene compliance. Compliance was also compared over five hand hygiene intervention periods. Descriptive statistics and multivariable logistic regression were used for analysis. Overall hand hygiene compliance was 58% (340/583). Two interventions had a significant positive association with hand hygiene compliance [improved signage with offering hand sanitizer, odds ratio (OR) 3·38, P<0·001; verbal hand hygiene reminders, OR 1·73, P=0·037]. There is clearly a need to improve hand hygiene compliance at this and other animal exhibits. This preliminary study was the first to demonstrate a positive impact of a hand hygiene intervention at a petting zoo. The findings suggest that active, rather than passive, interventions are more effective for increasing compliance.

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.

Epidemiology of Infectious Diarrhea

Diarrhea is a very frequent symptom. A great variety of chemical agents, microorganisms, and biotoxins can cause diarrhea, acute or persistent, slight or serious. From the epidemiological point of view, the cases can be sporadic or epidemic, and identification of the infection source and transmission mechanism is important for prevention and control. Knowledge of the etiology is a great help. The entrance route to the human body is usually through the digestive system. From some source in an individual's surroundings, the causal agent somehow reaches the mouth of the susceptible person. The hands play a fundamental role in many situations. This article revises the most important epidemiological characteristics of the agents that produce diarrhea as a main symptom, placing an emphasis on epidemiological point of view and environmental transmission mechanisms. Some aspects regarding individual susceptibility (genetic or other types) are also mentioned. Because the long-term consequences of infectious gastroenteritis are less well known, a small section dedicated to the long-term consequences of infectious gastroenteritis has been included. With suitable prevention, not only the acute consequences but also the aftereffects of these diseases can be avoided.