80 research outputs found
Public Health Microbiology of Shiga Toxin-Producing Escherichia coli.
ABSTRACT
Shiga toxin-producing
Escherichia coli
(STEC) strains are the only pathogenic group of
E. coli
that has a definite zoonotic origin, with ruminants and, in particular, cattle being recognized as the major reservoir. Most human STEC infections are food borne, but the routes of transmission include direct contact with animals and a variety of environment-related exposures. Therefore, STEC public health microbiology spans the fields of medical, veterinary, food, water, and environmental microbiology, requiring a "One Health" perspective and laboratory scientists with the ability to work effectively across disciplines. Public health microbiology laboratories play a central role in the surveillance of STEC infections, as well as in the preparedness for responding to outbreaks and in providing scientific evidence for the implementation of prevention and control measures. This article reviews (i) how the integration of surveillance of STEC infections and monitoring of these pathogens in animal reservoirs and potential food vehicles may contribute to their control; (ii) the role of reference laboratories, in both the public health and veterinary and food sectors; and (iii) the public health perspectives, including those related to regulatory issues in both the European Union and the United States
Waterborne outbreak of Norwalk-like virus gastroenteritis at a tourist resort, Italy.
In July 2000, an outbreak of gastroenteritis occurred at a tourist resort in the Gulf of Taranto in southern Italy. Illness in 344 people, 69 of whom were staff members, met the case definition. Norwalk-like virus (NLV) was found in 22 of 28 stool specimens tested. The source of illness was likely contaminated drinking water, as environmental inspection identified a breakdown in the resort water system and tap water samples were contaminated with fecal bacteria. Attack rates were increased (51.4%) in staff members involved in water sports. Relative risks were significant only for exposure to beach showers and consuming drinks with ice. Although Italy has no surveillance system for nonbacterial gastroenteritis, no outbreak caused by NLV has been described previously in the country
Isolation of Escherichia coli O157 in pigs at slaughter in Northern Italy
A study of VTEC 0157 intestinal carriage was performed in pigs at slaughter, carrying out surveys respectively in the Veneto and the Lombardia regions of Italy within a common research project. The study was conducted for 15 months, starting in June 2002. As a minimum, a sample size of 300 samples was defined for each survey, assuming an expected prevalence of 1%, C.l. 95%, accuracy 5% One gram samples of Intestinal content from the distal gut were tested for E. coli O157 using an isolation method based on immunomagnetic separation. In the survey performed in the Veneto region, all the 397 samples collected from pigs of 132 farms tested negative for VTEC O157, but one E. coli O157 harbouring the eae gene only was isolated. In the survey performed in the Lombardia region, VTEC 0157 was detected in 3 (0.63%, 95% C I 0.12- 1.81) of the 480 sampled p1gs from 3 (2.80%, 95% C.l. 0.58- 7.97) of the 107 farms of origin. Therefore in the study a total of 877 pigs were tested in 15 slaughters of two regions, with a prevalence of 0.34% 95% C.l. 0.07- 0 99) of positive pigs from 1.26% (95% C. I. 0.25- 3.62) of the herds. In one of the positive farms also cattle were reared with pigs, even if housed separately, and in a follow-up investigation VTEC 0157 strains sharing more than 96% homology with the pig strain were found in cattle
experiences in photogrammetric and laser scanner surveing of architectural heritage
The integration of different methodologies and simplification of procedures is surely one of the most important current themes in survey techniques for researching cultural heritage, especially for architectural heritage. The traditional methods for the metric survey of an architectural building (including micro geodesy and the stereophotogrammetric survey) are currently being consolidated. However, in the field of the architectural, artistic and archaeological survey, new technologies are now available and this knowledge needs to be more widely used, especially where the heritage is greater and so maintenance is as necessary as it is onerous. This report proposes some operative considerations, which derive from experience developed using the most modern technologies available, in order to compare and discuss the achievable accuracies (even if they are not always strictly necessary) and the operating modalities, especially for architectural surveys. So, the aim of this report is to verify that the simplification of procedures and cheaper solutions do not bring variations to the necessary metric precision or expert photointerpretation analysis. However, it is clear that, without considering the purposes and objectives of the survey, it would not be correct to appraise the survey methods and to classify those using reliability and accuracy criteria. In fact, the objective of a survey determines which tool will be used, according to the requests of the survey client to the survey expert
Shiga ToxinâProducing Escherichia coli Infections Associated with Hemolytic Uremic Syndrome, Italy, 1988â2000
The mean annual incidence of hemolytic uremic syndrome in persons <15 years of age in Italy from 1988 to 2000 was 0.28 per 100,000 population. Laboratory investigations showed that Shiga toxinâproducing Escherichia coli (STEC) infection occurred in 73.1% of patients. STEC O157 was the most common serotype, but a considerable number of cases were from infections by non-O157 STEC
Rapid Detection and Isolation of Escherichia coli O104:H4 from Milk Using Monoclonal Antibody-coated Magnetic Beads
Similarity of Shiga Toxinâproducing Escherichia coli O104:H4 Strains from Italy and Germany
Community-wide outbreak of haemolytic uraemic syndrome associated with Shiga toxin 2-producing Escherichia coli O26:H11 in southern Italy, summer 2013
In summer 2013, an excess of paediatric cases of haemolytic uraemic syndrome (HUS) in a southern region of Italy prompted the investigation of a community-wide outbreak of Shiga toxin 2-producing Escherichia coli (STEC) O26:H11 infections. Case finding was based on testing patients with HUS or bloody diarrhoea for STEC infection by microbiological and serological methods. A case-control study was conducted to identify the source of the outbreak. STEC O26 infection was identified in 20 children (median age 17 months) with HUS, two of whom reported severe neurological sequelae. No cases in adults were detected. Molecular typing showed that two distinct STEC O26:H11 strains were involved. The case-control study showed an association between STEC O26 infection and consumption of dairy products from two local plants, but not with specific ready-to-eat products. E.coli O26:H11 strains lacking the stx genes were isolated from bulk milk and curd samples, but their PFGE profiles did not match those of the outbreak isolates. This outbreak supports the view that infections with Stx2-producing E. coli O26 in children have a high probability of progressing to HUS and represent an emerging public health problem in Europe
Molecular and phenotypic typing of enteropathogenic Escherichia coli isolated in childhood acute diarrhea in Abuja, Nigeria
Introduction: Enteropathogenic Escherichia coli (EPEC) causes infectious diarrhea among children in developing countries. However, in Nigeria, due to limited laboratory resources, the genetic diversity of its virulence factors, which include intimin subtypes, remains undefined.
Methodology: EPEC isolates from diarrheic children 60 months of age and younger in Abuja, Nigeria, were analyzed. Polymerase chain reaction (PCR) for EPEC virulence gene, Hep-2 cell adherence, and serotyping were performed. EPEC strains were further subtyped by PCR for the identification of intimin subtype genes α (alpha), ÎČ (beta), Îł1 (gamma-1), and Î (epsilon). Antibiotic resistance and extended-spectrum beta-lactamase (ESBL) production was determined by Clinical and Laboratory Standards Institute guidelines.
Results: Overall, 18 (4.5%) out of 400 children with acute diarrhea had EPEC infection. Typical EPEC (tEPEC) strains were detected in 14 (3.5%), whereas 4 (1.1%) were atypical EPEC (aEPEC). A total of 15 (83.3%) of the EPEC isolated belonged to ÎČ intimin subtype gene, while the remaining 3 EPEC isolates possessed the intimin Î subtype. No α and Îł intimin subtypes were detected. Traditional EPEC serotypes O114:H14 were detected only in tEPEC strains. Marked resistance to ÎČ-lactam agents were observed but no ESBL-producing tEPEC or aEPEC was detected.
Conclusions: This is the first report of intimin subtype genes in Abuja, Nigeria. EPEC isolates of diverse serotypes resistant to ÎČ-lactam antimicrobial agents were observed. These data will be useful in facilitating the characterization of intimin variants of EPEC and some Shiga toxin-producing E. coli (STEC) in humans and other animal species
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