scholarly journals Quantifying within- and between-animal variation and uncertainty associated with counts of Escherichia coli O157 occurring in naturally infected cattle faeces

2008 ◽  
Vol 6 (31) ◽  
pp. 169-177 ◽  
Author(s):  
S.E Robinson ◽  
P.E Brown ◽  
E.J Wright ◽  
C.A Hart ◽  
N.P French
Keyword(s):  
Escherichia Coli ◽  
Statistical Model ◽  
Human Infection ◽  
Microbial Count ◽  
Infected Cattle ◽  
Explanatory Variables ◽  
E Coli ◽  
Fixed And Random Effects ◽  
Cattle Faeces ◽  
Multiple Samples

Cattle faeces are considered the most important reservoir for human infection with Escherichia coli O157. We have previously described shedding of E. coli O157 in the faeces of naturally infected cattle cohorts. However, the data require further investigation to quantify the uncertainty and variability in the estimates previously presented. This paper proposes a method for analysing both the presence and the quantity of E. coli O157 in cattle faecal samples, using two isolation procedures, one of which enumerates E. coli O157. The combination of these two measurements, which are fundamentally different in nature and yet measuring a common outcome, has necessitated the development of a novel statistical model for ascertaining the contribution of the various components of variation (both natural and observation induced) and for judging the influence of explanatory variables. Most of the variation within the sampling hierarchy was attributable to multiple samples from the same animal. The contribution of laboratory-level variation was found to be low. After adjusting for fixed and random effects, short periods of increased intensity of shedding were identified in individual animals. We conclude that within-animal variation is greater than between animals over time, and studies aiming to elucidate the dynamics of shedding should focus resources, sampling more within than between animals. These findings have implications for the identification of persistent high shedders and for assessing their role in the epidemiology of E. coli O157 in cattle populations. The development of this non-standard statistical model may have many applications to other microbial count data.

scholarly journals A Statistical Model for Assessing Sample Size for Bacterial Colony Selection: A Case Study of Escherichia Coli and Avian Cellulitis

2000 ◽  
Vol 12 (2) ◽  
pp. 118-125 ◽  
Author(s):  
Randall S. Singer ◽  
Wesley O. Johnson ◽  
Joan S. Jeffrey ◽  
Richard P. Chin ◽  
Tim E. Carpenter ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Statistical Model ◽  
Clinical Sample ◽  
Agar Plate ◽  
Sample Sizes ◽  
Simple Task ◽  
Single Strain ◽  
Bacterial Colony ◽  
E Coli

A general problem for microbiologists is determining the number of phenotypically similar colonies growing on an agar plate that must be analyzed in order to be confident of identifying all of the different strains present in the sample. If a specified number of colonies is picked from a plate on which the number of unique strains of bacteria is unknown, assigning a probability of correctly identifying all of the strains present on the plate is not a simple task. With Escherichia coli of avian cellulitis origin as a case study, a statistical model was designed that would delineate sample sizes for efficient and consistent identification of all the strains of phenotypically similar bacteria in a clinical sample. This model enables the microbiologist to calculate the probability that all of the strains contained within the sample are correctly identified and to generate probability-based sample sizes for colony identification. The probability of cellulitis lesions containing a single strain of E. coli was 95.4%. If one E. coli strain is observed out of three colonies randomly selected from a future agar plate, the probability is 98.8% that only one strain is on the plate. These results are specific for this cellulitis E. coli scenario. For systems in which the number of bacterial strains per sample is variable, this model provides a quantitative means by which sample sizes can be determined.

scholarly journals Monitoring antimicrobial resistance trends in commensal Escherichia coli from livestock, the Netherlands, 1998 to 2016

2019 ◽  
Vol 24 (25) ◽  
Author(s):  
Ayla Hesp ◽  
Kees Veldman ◽  
Jeanet van der Goot ◽  
Dik Mevius ◽  
Gerdien van Schaik
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Monitoring Data ◽  
Resistant Isolate ◽  
Similar Data ◽  
Explanatory Variables ◽  
E Coli ◽  
Veal Calves ◽  
Before And After ◽  
Using Data

Background Monitoring of antimicrobial resistance (AMR) in animals is essential for public health surveillance. To enhance interpretation of monitoring data, evaluation and optimisation of AMR trend analysis is needed. Aims To quantify and evaluate trends in AMR in commensal Escherichia coli, using data from the Dutch national AMR monitoring programme in livestock (1998–2016). Methods Faecal samples were collected at slaughter from broilers, pigs and veal calves. Minimum inhibitory concentration values were obtained by broth microdilution for E. coli for 15 antimicrobials of eight antimicrobial classes. A Poisson regression model was applied to resistant isolate counts, with explanatory variables representing time before and after 2009 (reference year); for veal calves, sampling changed from 2012 represented by an extra explanatory variable. Results Resistant counts increased significantly from 1998-2009 in broilers and pigs, except for tetracyclines and sulfamethoxazole in broilers and chloramphenicol and aminoglycosides in pigs. Since 2009, resistant counts decreased for all antimicrobials in broilers and for all but the phenicols in pigs. In veal calves, for most antimicrobials no significant decrease in resistant counts could be determined for 2009–16, except for sulfamethoxazole and nalidixic acid. Within animal species, antimicrobial-specific trends were similar. Conclusions Using Dutch monitoring data from 1998-2016, this study quantified AMR trends in broilers and slaughter pigs and showed significant trend changes in the reference year 2009. We showed that monitoring in commensal E. coli is useful to quantify trends and detect trend changes in AMR. This model is applicable to similar data from other European countries.

scholarly journals Comparison between human and animal isolates of Shiga toxin-producing Escherichia coli O157 from Australia

2002 ◽  
Vol 128 (3) ◽  
pp. 357-362 ◽  
Author(s):  
N. FEGAN ◽  
P. DESMARCHELIER
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Human Infection ◽  
Pulsed Field Gel Electrophoresis ◽  
Toxin Gene ◽  
Escherichia Coli O157 ◽  
Animal Population ◽  
E Coli ◽  
Virulence Markers ◽  
Animal Isolates

There is very little human disease associated with enterohaemorrhagic Escherichia coli O157 in Australia even though these organisms are present in the animal population. A group of Australian isolates of E. coli O157:H7 and O157:H- from human and animal sources were tested for the presence of virulence markers and compared by XbaI DNA macrorestriction analysis using pulsed-field gel electrophoresis (PFGE). Each of 102 isolates tested contained the gene eae which encodes the E. coli attaching and effacing factor and all but one carried the enterohaemolysin gene, ehxA, found on the EHEC plasmid. The most common Shiga toxin gene carried was stx2c, either alone (16%) or in combination with stx1 (74%) or stx2 (3%). PFGE grouped the isolates based on H serotype and some clusters were source specific. Australian E. coli O157:H7 and H- isolates from human, animal and meat sources carry all the virulence markers associated with EHEC disease in humans therefore other factors must be responsible for the low rates of human infection in Australia.

Prevalence of shiga toxin-producing Escherichia coli O157, O26 and O111 in milk, meat and faeces of cattle, sheep and pigs slaughtered in Benin

2020 ◽  
Vol 152 ◽  
pp. 15667-15675
Author(s):  
Chakirath Folakè Arikè Salifou ◽  
Cyrille Boko ◽  
Isidore Houaga ◽  
Raoul Agossa ◽  
Isabelle Ogbankotan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Animal Origin ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Milk Samples ◽  
Food Of Animal Origin ◽  
Cattle Faeces ◽  
Risk Assessment And Management

Objectives: The study aimed to search for E. coli O157 and non-O157 in milk, meat and faeces of cattle, sheep and pigs slaughtered in Cotonou. Methodology and Results: One hundred and Seventy-Five (175) samples including 25 meat, 25 faeces per species and 25 milk from cattle were analysed for E. coli O157; O26 and O111 and the virulence genes were identified by PCR. The SAS software (1998) and the bilateral Z test were used to calculate and compare the identification frequencies. E. coli O157 was identified in 4% of cattle faeces, 4% of sheep faeces, and 20% of beef and, in 20% of milk samples. E. coli O26 was identified in 12% of cattle faeces and, in 8% of beef samples. E. coli O111 was identified at frequencies of 8%, and 12% in faeces of sheep and pigs, respectively. The eae gene was detected in 4% of beef, ovine meat, milk, pig faeces and in sheep faeces. stx1 was detected in 8% of milk, and in 4% of bovine and sheep faeces. The strains possessing the gene were all of E. coli O157 with the exception of one from pig faeces identified as O111. Conclusions and application of findings: The presence of these serogroups of E. coli with virulence genes poses a real food safety problem in Benin. This study findings must be taken into account for risk assessment and management related to the consumption of food of animal origin. Keywords: Benin, E. coli O157, O26, O111, faeces, meat, milk

scholarly journals Escherichia coli O157[ratio ]H7 infection of calves: infectious dose and direct contact transmission

2001 ◽  
Vol 127 (3) ◽  
pp. 555-560 ◽  
Author(s):  
T. E. BESSER ◽  
B. L. RICHARDS ◽  
D. H. RICE ◽  
D. D. HANCOCK
Keyword(s):  
Escherichia Coli ◽  
Direct Contact ◽  
Reservoir Host ◽  
Human Infection ◽  
Escherichia Coli O157 ◽  
Faecal Excretion ◽  
Infectious Dose ◽  
E Coli ◽  
Electrophoretic Patterns ◽  
Contact Transmission

Cattle are considered to be a reservoir host of Escherichia coli O157[ratio ]H7 and contaminated foods of bovine origin are important vehicles of human infection. In this study, the susceptibility of calves to experimental E. coli O157[ratio ]H7 infection following low oral exposures was determined. Two of 17 calves exposed to very low (<300 c.f.u.) doses, and 3 of 4 calves exposed to low (<10000 c.f.u.) doses, subsequently excreted the challenge strains in their faeces. All calves (n = 12) sharing isolation rooms with calves that excreted the challenge strain in their faeces similarly began faecal excretion of the same strains within 21 days or less. The identity between the challenge strains and the strains excreted in calf faeces was confirmed by restriction digestion electrophoretic patterns using pulsed field gel electrophoresis. Calves shed E. coli O157[ratio ]H7 in their faeces after very low dose exposures at concentrations ranging from <30 to >107 c.f.u./g, and for durations similar to the values previously reported for calves challenged by larger doses. The susceptibility of calves to infection following very low exposures or direct contact with infected calves has important implications for programmes for pre-harvest control of this agent.

Predicting Survival of Escherichia coli O157:H7 in Dry Fermented Sausage Using Artificial Neural Networks

2008 ◽  
Vol 71 (1) ◽  
pp. 6-12 ◽  
Author(s):  
A. PALANICHAMY ◽  
D. S. JAYAS ◽  
R. A. HOLLEY
Keyword(s):  
Escherichia Coli ◽  
Neural Networks ◽  
Artificial Neural Networks ◽  
Statistical Model ◽  
Allyl Isothiocyanate ◽  
Escherichia Coli O157 ◽  
Fermented Sausage ◽  
E Coli ◽  
Dry Fermented Sausage ◽  
Artificial Neural

The Canadian Food Inspection Agency required the meat industry to ensure Escherichia coli O157:H7 does not survive (experiences ≥ 5 log CFU/g reduction) in dry fermented sausage (salami) during processing after a series of foodborne illness outbreaks resulting from this pathogenic bacterium occurred. The industry is in need of an effective technique like predictive modeling for estimating bacterial viability, because traditional microbiological enumeration is a time-consuming and laborious method. The accuracy and speed of artificial neural networks (ANNs) for this purpose is an attractive alternative (developed from predictive microbiology), especially for on-line processing in industry. Data from a study of interactive effects of different levels of pH, water activity, and the concentrations of allyl isothiocyanate at various times during sausage manufacture in reducing numbers of E. coli O157:H7 were collected. Data were used to develop predictive models using a general regression neural network (GRNN), a form of ANN, and a statistical linear polynomial regression technique. Both models were compared for their predictive error, using various statistical indices. GRNN predictions for training and test data sets had less serious errors when compared with the statistical model predictions. GRNN models were better and slightly better for training and test sets, respectively, than was the statistical model. Also, GRNN accurately predicted the level of allyl isothiocyanate required, ensuring a 5-log reduction, when an appropriate production set was created by interpolation. Because they are simple to generate, fast, and accurate, ANN models may be of value for industrial use in dry fermented sausage manufacture to reduce the hazard associated with E. coli O157:H7 in fresh beef and permit production of consistently safe products from this raw material.

scholarly journals Use of In Vivo-Induced Antigen Technology for Identification of Escherichia coli O157:H7 Proteins Expressed during Human Infection

2005 ◽  
Vol 73 (5) ◽  
pp. 2665-2679 ◽  
Author(s):  
Manohar John ◽  
Indira T. Kudva ◽  
Robert W. Griffin ◽  
Allen W. Dodson ◽  
Bethany McManus ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Vaccine Development ◽  
Human Infection ◽  
Escherichia Coli O157 ◽  
Standard Laboratory ◽  
E Coli ◽  
Phase Culture ◽  
Stool Specimens

ABSTRACT Using in vivo-induced antigen technology (IVIAT), a modified immunoscreening technique that circumvents the need for animal models, we directly identified immunogenic Escherichia coli O157:H7 (O157) proteins expressed either specifically during human infection but not during growth under standard laboratory conditions or at significantly higher levels in vivo than in vitro. IVIAT identified 223 O157 proteins expressed during human infection, several of which were unique to this study. These in vivo-induced (ivi) proteins, encoded by ivi genes, mapped to the backbone, O islands (OIs), and pO157. Lack of in vitro expression of O157-specific ivi proteins was confirmed by proteomic analysis of a mid-exponential-phase culture of E. coli O157 grown in LB broth. Because ivi proteins are expressed in response to specific cues during infection and might help pathogens adapt to and counter hostile in vivo environments, those identified in this study are potential targets for drug and vaccine development. Also, such proteins may be exploited as markers of O157 infection in stool specimens.

scholarly journals Escherichia Coli O157:H7: Distribution, molecular characterization, antimicrobial resistance patterns and source of contamination of sheep and goat carcasses at an export Abattoir, Mojdo, Ethiopia

2019 ◽  
Author(s):  
Solomon Abreham ◽  
Akafete Teklu ◽  
Eric Cox ◽  
Tesfaye Sisay Tessema
Keyword(s):  
Escherichia Coli ◽  
Molecular Characterization ◽  
Virulence Genes ◽  
Antibiotic Sensitivity ◽  
Latex Agglutination ◽  
Human Infection ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Source Of Infection ◽  
Resistance Patterns

Abstract Background : Cattle have been identified as a major reservoir of E. coli O157:H7 for human infection; the ecology of the organism in sheep and goats is less understood. This study was carried out to determine prevalence, source of infection, antibiotic resistance and molecular characterization of Escherichia coli O157: H7 isolated from sheep and goat. Methods : Systematic random sampling was carried out at Modjo export abattoir, Ethiopia, from November 2012 to April 2013 to collect 408 samples from 72 sheep and 32 goats. Samples collected were skin swabs, fecal samples, intestinal mucosal swabs and the inside and outside part of carcasses as well as carcass in contacts such as workers hands, knife, hook and carcass washing water. Then, samples were processed following standard bacteriological procedures. Non-Sorbitol fermenting colonies were tested on latex agglutination test and the positives are subjected to PCR for detection of attaching and effacing genes ( eaeA) and shiga toxin producing genes ( stx1 and stx2 ). All E. coli O157:H7 isolates were checked for their susceptibility pattern towards 15 selected antibiotics. Results : E. coli O157:H7 were detected in only 20/408 samples (4.9%). Among these 20 positive samples, 70% (14/20), 25% (5/20) and 5% (1/20) were from sheep, goats and knife samples, respectively. No significant associations were found between carcasses and the assumed sources of contaminations. Of all the 20 isolates virulence genes were found in 10 (50%) of them; 3 (15%) with only the eaeA gene and 7(35%) expressing eaeA and stx2 genes. All the isolates were susceptible to Norfloxacin (NOR) (100%). Conclusions : The presence of virulence genes shows E. coli O157:H7 is a potential source of human infection in Ethiopia. Key words : Abattoir, antibiotic sensitivity, CT-SMAC, E. coli O157:H7, IMS, Latex agglutination, multiplex PCR.

scholarly journals UJI TOKSISITAS ESCHERICHIA COLI ASAL DAGING TERHADAP SEL VERO

2018 ◽  
Vol 18 (2) ◽  
Author(s):  
Widodo Suwito ◽  
Andriani Andriani
Keyword(s):  
Escherichia Coli ◽  
Vero Cell ◽  
Key Words ◽  
Vero Cells ◽  
E Coli ◽  
Traditional Market ◽  
Cattle Faeces

Abstract: Verotoxigenic Escherichia coli (VTEC) is responsible for serious human illnesses. Source of VTEC is cattle faeces which beef contamination. The aims of this study was to determine the ability of E. coli which beef contamination from traditional market to damage the vero cells monolayer. A total of 35 E. coli isolates and vero cells monolayer were used in these study. All isolates E. coli were re-indentified with biochemistry and vero cells monolayer were uesed to determination verotoxigenecity tests. None of E. coli isolates showed damage the vero cells monolayer, so there are not verotoxigenik E. coli. The study showed that all isolate E. coli which beef contamination from tradiotional market none damage the vero cells, so there are not verotoxigenic. Key words: E.coli, beef, vero cell Abstrak: Escherichia coli verotoksigenik (VTEC) menyebabkan penyakit pada manusia. Sumber VTEC adalah feses sapi yang dapat mengkontaminasi daging. Tujuan penelitian ini adalah mengetahui kemampuan E. coli yang diisolasi dari daging sapi di pasar tradisional dalam merusak sel vero monolayer. Sebanyak 35 isolat E. coli dan sel vero monolayer digunakan dalam penelitian ini. Isolat E. coli di identifikasi ulang secara biokimia dan untuk menentukan sifat verotoksigenesitasnya menggunakan sel vero monolayer. Semua isolat E. coli tidak bersifat verotoksigenik karena tidak mampu merusak sel vero. Penelitian ini menunjukkan bahwa E. coli yang mengkontaminasi daging sapi dari pasar tradisional tidak bersifat verotoksigenik.  Kata kunci: E.coli, daging, sel vero. 

scholarly journals Shiga toxin-producing Escherichia coli (STEC) food-borne outbreaks

2017 ◽  
Vol 63 (1) ◽  
pp. 45 ◽  
Author(s):  
A. PEXARA (Α. ΠΕΞΑΡΑ) ◽  
A. S. ANGELIDIS (Α. Σ. ΑΓΓΕΛΙΔΗΣ) ◽  
A. GOVARIS (Α. ΓΚΟΒΑΡΗΣ)
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Intestinal Flora ◽  
Food Poisoning ◽  
Significant Risk ◽  
Public Health Problem ◽  
Human Infection ◽  
Food Sources ◽  
E Coli ◽  
Food Borne

Escherichia coli (E. coli) are Gram negativo, non-sporulating bacteria, which belong to the normal intestinal flora of humans and animals. Shiga toxin-producing E. coli (STFC) arc a group of if. coli that is defined by the capacity to produce toxins called Shiga toxins (Stx). hollowing ingestion of STEC, the significant risk of two serious and potentially life-threatening complications of infection, hemorrhagic colitis and hemolytic uremic syndrome (HUS), makes STHC food poisoning a serious public health problem. Besides Stx, human pathogenic STFC harbor additional virulence factors that are important for their pathogenicity. Although human infection may also be acquired by direct transmission from person to person or by direct contact of humans with animal carriers, the majority of STFC infections are food-borne in origin.The gastrointestinal tract of healthy ruminants seems to be the foremost important reservoir for STFC and ingestion of undercooked beef one of the most likely routes of transmission to humans, Other important food sources include faecally contaminated vegetables and drinking water, The serogroup classification of STHC is based on the somatic (O) and flagellar (H) antigens, and, to date, more than 200 STFC serogroups have been identified, Human STFC infections are, however, associated with a minor subset of 0;H serotypes. Of these, the 0157:H7 or the 0157 :H- serogroups (STFC 0157) are the ones most frequently reported to be associated with food-borne outbreaks. However other non-0157 STFC serogroups such as E. coli 026, 0103, O l l i , 012I, 045 and 0145 have caused several outbreaks in recent years.Two outbreaks of gastroenteritis caused by E. coli 0157:117 were first reported in the US, following the consumption of undercooked hamburgers, in 1982. Since then several outbreaks were reported worldwide. A major E. coli 0157:117 outbreak occurred in Japan and contaminated radish sprouts was identified as the vehicle of infection. More than 6,000 school children were affected, 101 people were hospitalized with lILS and 12 deaths were recorded. The recent outbreak of STFC 0104:114 infection and HUS reported in Germany in the spring of 2011 was one of the largest outbreaks worldwide. As of 27 July, 3 126 cases of STFC infections, 773 cases of HUS including 46 deaths linked to the outbreak in Germany and occurring in the Furopean Union (FU) (including Norway), Outside the FU 8 cases of STFC and 5 cases of HUS, including 1 death have been reported in the USA, Canada and Switzerland, all with recent travel history to Germany.The present review on major STliC food-borne outbreaks recorded worldwide highlights the need for eontrol measures in order to prevent or at least minimize the occurrence of similar events in the future.

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