scholarly journals Longitudinal Study of Escherichia coli O157:H7 in a Beef Cattle Feedlot and Role of High-Level Shedders in Hide Contamination

2009 ◽  
Vol 75 (20) ◽  
pp. 6515-6523 ◽  
Author(s):  
Terrance M. Arthur ◽  
James E. Keen ◽  
Joseph M. Bosilevac ◽  
Dayna M. Brichta-Harhay ◽  
Norasak Kalchayanand ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Longitudinal Study ◽  
Beef Cattle ◽  
Intervention Studies ◽  
High Density ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
High Level ◽  
Cattle Feedlot

ABSTRACT The objectives of the study described here were (i) to investigate the dynamics of Escherichia coli O157:H7 fecal and hide prevalence over a 9-month period in a feedlot setting and (ii) to determine how animals shedding E. coli O157:H7 at high levels affect the prevalence and levels of E. coli O157:H7 on the hides of other animals in the same pen. Cattle (n = 319) were distributed in 10 adjacent pens, and fecal and hide levels of E. coli O157:H7 were monitored. When the fecal pen prevalence exceeded 20%, the hide pen prevalence was usually (25 of 27 pens) greater than 80%. Sixteen of 19 (84.2%) supershedder (>104 CFU/g) pens had a fecal prevalence greater than 20%. Significant associations with hide and high-level hide (≥40 CFU/100 cm2) contamination were identified for (i) a fecal prevalence greater than 20%, (ii) the presence of one or more high-density shedders (≥200 CFU/g) in a pen, and (iii) the presence of one or more supershedders in a pen. The results presented here suggest that the E. coli O157:H7 fecal prevalence should be reduced below 20% and the levels of shedding should be kept below 200 CFU/g to minimize the contamination of cattle hides. Also, large and unpredictable fluctuations within and between pens in both fecal and hide prevalence of E. coli O157:H7 were detected and should be used as a guide when preharvest studies, particularly preharvest intervention studies, are designed.

scholarly journals Molecular survey of mcr1 and mcr2 plasmid mediated colistin resistance genes in Escherichia coli isolates of animal origin in Iran

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Kayhan Ilbeigi ◽  
Mahdi Askari Badouei ◽  
Hossein Vaezi ◽  
Hassan Zaheri ◽  
Sina Aghasharif ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Companion Animals ◽  
Multidrug Resistant ◽  
Animal Origin ◽  
Colistin Resistance ◽  
E Coli ◽  
High Level ◽  
Farming Industry

Abstract Objectives The emergence of colistin-resistant Enterobacteriaceae from human and animal sources is one of the major public health concerns as colistin is the last-resort antibiotic for treating infections caused by multidrug-resistant Gram-negative bacteria. We aimed to determine the prevalence of the prototype widespread colistin resistance genes (mcr-1 and mcr-2) among commensal and pathogenic Escherichia coli strains isolated from food-producing and companion animals in Iran. Results A total of 607 E. coli isolates which were previously collected from different animal sources between 2008 and 2016 used to uncover the possible presence of plasmid-mediated colistin resistance genes (mcr-1 and mcr-2) by PCR. Overall, our results could not confirm the presence of any mcr-1 or mcr-2 positive E. coli among the studied isolates. It is concluded that despite the important role of food-producing animals in transferring the antibiotic resistance, they were not the main source for carriage of mcr-1 and mcr-2 in Iran until 2016. This study suggests that the other mcr variants (mcr-3 to mcr-9) might be responsible for conferring colistin resistance in animal isolates in Iran. The possible linkage between pig farming industry and high level of mcr carriage in some countries needs to be clarified in future prospective studies.

Fate of Escherichia coli O157:H7 and Other Coliforms in Commercial Mayonnaise and Refrigerated Salad Dressing

1995 ◽  
Vol 58 (1) ◽  
pp. 13-18 ◽  
Author(s):  
ERROL V. RAGHUBEER ◽  
JIM S. KE ◽  
MICHAEL L. CAMPBELL ◽  
RICHARD S. MEYER
Keyword(s):  
Escherichia Coli ◽  
Storage Temperature ◽  
Enterobacter Aerogenes ◽  
Antimicrobial Effect ◽  
Coliform Bacteria ◽  
Escherichia Coli O157 ◽  
Salad Dressing ◽  
E Coli ◽  
Survival Pattern ◽  
High Level

Commercial mayonnaise and refrigerated ranch salad dressing were inoculated at two levels with two strains of Escherichia coli O157:H7, a non-pathogenic E. coli, and the non-fecal coliform Enterobacter aerogenes. Results showed that at the high inoculation level (>106 colony forming units [CFU]/g) in mayonnaise stored at room temperature (ca. 22°C) both strains of O157:H7 were undetected at 96 h. At the high inoculation level, all strains of coliform bacteria tested survived longer in salad dressing stored at 4°C than in mayonnaise stored at 22°C. The O157:H7 strains were still present at low levels after 17 days. The survival time in the low-level inoculum (104CFU/g) study decreased, but the survival pattern in the two products was similar to that observed in the high-level inoculum study. Slight differences in survival among strains were observed. The greater antimicrobial effect of mayonnaise may be attributable to differences in pH, water activity (aw), nutrients, storage temperature, and the presence of lysozyme in the whole eggs used in the production of commercial mayonnaise. Coliform bacteria survived longer in refrigerated salad dressing than in mayonnaise particularly at the high-level inoculum. Both mayonnaise (pH 3.91) and salad dressing (pH 4.51) did not support the growth of any of the microorganisms even though survival was observed.

Quantitative Determination of the Role of Lettuce Leaf Structures in Protecting Escherichia coli O157:H7 from Chlorine Disinfection

2001 ◽  
Vol 64 (2) ◽  
pp. 147-151 ◽  
Author(s):  
KAZUE TAKEUCHI ◽  
JOSEPH F. FRANK
Keyword(s):  
Escherichia Coli ◽  
Leaf Surface ◽  
Dead Cell ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Chlorine Disinfection ◽  
Sytox Green ◽  
Tissue Surface ◽  
Confocal Scanning

Viability of Escherichia coli O157:H7 cells on lettuce leaves after 200 mg/liter (200 ppm) chlorine treatment and the role of lettuce leaf structures in protecting cells from chlorine inactivation were evaluated by confocal scanning microscopy (CSLM). Lettuce samples (2 by 2 cm) were inoculated by immersing in a suspension containing 109 CFU/ml of E. coli O157: H7 for 24 ± 1 h at 4°C. Rinsed samples were treated with 200 mg/liter (200 ppm) chlorine for 5 min at 22°C. Viability of E. coli O157:H7 cells was evaluated by CSLM observation of samples stained with Sytox green (dead cell stain) and Alexa 594 conjugated antibody against E. coli O157:H7. Quantitative microscopic observations of viability were made at intact leaf surface, stomata, and damaged tissue. Most E. coli O157:H7 cells (68.3 ± 16.2%) that had penetrated 30 to 40 μm from the damaged tissue surface remained viable after chlorine treatment. Cells on the surface survived least (25.2 ± 15.8% survival), while cells that penetrated 0 to 10 μm from the damaged tissue surface or entered stomata showed intermediate survival (50.8 ± 13.5 and 45.6 ± 9.7% survival, respectively). Viability was associated with the depth at which E. coli O157:H7 cells were in the stomata. Although cells on the leaf surface were mostly inactivated, some viable cells were observed in cracks of cuticle and on the trichome. These results demonstrate the importance of lettuce leaf structures in the protection of E. coli O157:H7 cells from chlorine inactivation.

scholarly journals ‘Super' or just ‘above average'? Supershedders and the transmission of Escherichia coli O157:H7 among feedlot cattle

2015 ◽  
Vol 12 (110) ◽  
pp. 20150446 ◽  
Author(s):  
Simon E. F. Spencer ◽  
Thomas E. Besser ◽  
Rowland N. Cobbold ◽  
Nigel P. French
Keyword(s):  
Escherichia Coli ◽  
Stocking Density ◽  
Preliminary Evidence ◽  
Feedlot Cattle ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Key Characteristics ◽  
Data Driven Approach ◽  
Definition Of

Supershedders have been suggested to be major drivers of transmission of Escherichia coli O157:H7 ( E. coli O157:H7) among cattle in feedlot environments, despite our relatively limited knowledge of the processes that govern periods of high shedding within an individual animal. In this study, we attempt a data-driven approach, estimating the key characteristics of high shedding behaviour, including effects on transmission to other animals, directly from a study of natural E. coli O157:H7 infection of cattle in a research feedlot, in order to develop an evidence-based definition of supershedding. In contrast to the hypothesized role of supershedders, we found that high shedding individuals only modestly increased the risk of transmission: individuals shedding over 10 3 cfu g −1 faeces were estimated to pose a risk of transmission only 2.45 times greater than those shedding below that level. The data suggested that shedding above 10 3 cfu g −1 faeces was the most appropriate definition of supershedding behaviour and under this definition supershedding was surprisingly common, with an estimated prevalence of 31.3% in colonized individuals. We found no evidence that environmental contamination by faeces of shedding cattle contributed to transmission over timescales longer than 3 days and preliminary evidence that higher stocking density increased the risk of transmission.

Comparison of the Molecular Genotypes of Escherichia coli O157:H7 from the Hides of Beef Cattle in Different Regions of North America†

2007 ◽  
Vol 70 (7) ◽  
pp. 1622-1626 ◽  
Author(s):  
TERRANCE M. ARTHUR ◽  
JOSEPH M. BOSILEVAC ◽  
XIANGWU NOU ◽  
STEVEN D. SHACKELFORD ◽  
TOMMY L. WHEELER ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
North America ◽  
Beef Cattle ◽  
The United States ◽  
Pathogen Transmission ◽  
Source Tracking ◽  
Escherichia Coli O157 ◽  
Pfge Analysis ◽  
Multiple Sources ◽  
E Coli

Cattle hides become contaminated with Escherichia coli O157:H7 via pathogen transmission in the feedlot, during transport, and while in the lairage environment at the processing facility, and the bacteria can be transferred to beef carcasses during processing. Several studies have shown that E. coli O157:H7 strains possessing indistinguishable restriction digest patterns (RDPs) can be isolated from distant locations. Most of these studies, however, examined RDPs from strains isolated within a single region of the United States or Canada. The experiment described in the present study was designed to identify the molecular genotypes of E. coli O157:H7 isolates from beef cattle hides in nine major cattle-producing regions of North America. Prevalence for E. coli O157:H7 in beef cattle hide samples ranged from 9 to 85%. Pulsed-field gel electrophoresis (PFGE) analysis of XbaI-digested genomic DNA from 1,193 E. coli O157:H7 isolates resulted in 277 unique RDPs. Of the 277 unique XbaI RDPs, 54 contained isolates collected from multiple regions. After two subsequent rounds of PFGE analysis (BlnI and SpeI), there were still many isolates (n = 154) that could not be distinguished from others, even though they were collected from different regions separated by large geographical distances. On multiple occasions, strains isolated from cattle hides in Canada had RDPs that were indistinguishable after three enzyme digestions from cattle hide isolates collected in Kansas and Nebraska. This information clearly shows that strains with indistinguishable RDPs originate from multiple sources that can be separated by large distances and that this should be taken into account when the source tracking of isolates is based on PFGE.

Seasonal Prevalence of Escherichia coli O157:H7 in Beef Cattle Feces†

2006 ◽  
Vol 69 (12) ◽  
pp. 3018-3020 ◽  
Author(s):  
M. J. ALAM ◽  
L. ZUREK
Keyword(s):  
Escherichia Coli ◽  
Beef Cattle ◽  
Shiga Toxin ◽  
Bacterial Colonization ◽  
Feedlot Cattle ◽  
Escherichia Coli O157 ◽  
Human Pathogen ◽  
E Coli ◽  
Cattle Feces ◽  
Shiga Toxin 2

Cattle are an asymptomatic reservoir of Escherichia coli O157:H7, but the bacterial colonization and shedding patterns are poorly understood. The prevalence and shedding of this human pathogen have been reported to be seasonal with rates typically increasing during warm months. The objectives of this study were (i) to assess the prevalence of E. coli O157:H7 in feces of feedlot cattle in Kansas during summer, fall, and winter months, and (ii) to characterize E. coli O157:H7 by screening for virulence factors. Of 891 fecal samples collected, 82 (9.2%) were positive for E. coli O157:H7. No significant differences in prevalence were detected among summer, fall, and winter months. The highest monthly prevalence (18.1%) was detected in February. All tested isolates were positive for stx2 (Shiga toxin 2) and eaeA (intimin) genes; 14 isolates (12.8%) also carried stx1. Our results indicate the prevalence of E. coli O157:H7 in beef cattle feces is not necessarily season dependent.

Effects of a Minimal Hide Wash Cabinet on the Levels and Prevalence of Escherichia coli O157:H7 and Salmonella on the Hides of Beef Cattle at Slaughter†

2007 ◽  
Vol 70 (5) ◽  
pp. 1076-1079 ◽  
Author(s):  
TERRANCE M. ARTHUR ◽  
JOSEPH M. BOSILEVAC ◽  
DAYNA M. BRICHTA-HARHAY ◽  
NORASAK KALCHAYANAND ◽  
STEVEN D. SHACKELFORD ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Beef Cattle ◽  
Limit Of Detection ◽  
Intervention Strategy ◽  
Medium Size ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Beef Processing ◽  
Before And After ◽  
Processing Plants

Harborage of Escherichia coli O157:H7 and Salmonella on animal hides at slaughter is the main source of beef carcass contamination during processing. Given this finding, interventions have been designed and implemented to target the hides of cattle following entry into beef processing plants. Previous interventions targeting hides have not been suitable for all beef processing plants because of cost and space restrictions. In this study, a hide wash cabinet was evaluated to determine whether it was more amenable to widespread use in the beef processing industry, especially for small and medium-size plants. Overall, 101 (35.1%) of 288 beef cattle hides sampled before entry into the hide wash cabinet harbored E. coli O157:H7 at or above the limit of detection (40 CFU/100 cm2). After passage through the hide wash cabinet, only 38 (13.2%) of 288 hides had E. coli O157:H7 levels ≥40 CFU/100 cm2. Before the hide wash cabinet, 50 (17%) of 288 hides harbored E. coli O157:H7 at levels above 100 CFU/100 cm2, with one sample as high as 20,000 CFU/100 cm2. In contrast, only 14 (5%) of 288 hides had E. coli O157:H7 levels above 100 CFU/100 cm2 after hide washing, with the highest being 2,000 CFU/100 cm2. These same trends also were found for Salmonella before and after hide washing. These results indicate that the hide wash cabinet described in this study was effective and should provide small and medium-size processing plants with an affordable hide wash intervention strategy.

Escherichia coli O157 Prevalence in Different Cattle Farm Types and Identification of Potential Risk Factors

2009 ◽  
Vol 72 (9) ◽  
pp. 1848-1853 ◽  
Author(s):  
K. COBBAUT ◽  
D. BERKVENS ◽  
K. HOUF ◽  
R. DE DEKEN ◽  
L. DE ZUTTER
Keyword(s):  
Escherichia Coli ◽  
Beef Cattle ◽  
Dairy Cattle ◽  
Farm Size ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Multiplex Pcr Assay ◽  
Farm Type ◽  
Veal Calf ◽  
Cattle Farms

Although the prevalence of Escherichia coli O157 on cattle farms has been examined extensively, the relationship between this pathogen and farm type has been established only rarely. A large-scale study was designed to determine the prevalence of E. coli O157 in the Flemish region of Belgium on farms of dairy cattle, beef cattle, mixed dairy and beef cattle, and veal calves. The effect of various factors on the occurrence at the pen level also was evaluated. In 2007, 180 farms were randomly selected based on region, farm size, and number of animals purchased and were examined using the overshoe sampling method. When possible, overshoes used in areas containing animals in three different age categories (<8 months, 8 to 30 months, and >30 months) were sampled on each farm. In total, 820 different pens were sampled and analyzed for the presence of E. coli O157 by enrichment, immunomagnetic separation, and plating on selective agar. Presumptive E. coli O157 colonies were identified using a multiplex PCR assay for the presence of the rfbO157 and fliCH7 genes. The statistical analysis was carried out with Stata SE/10.0 using a generalized linear regression model with a logit link function and a binomial error distribution. The overall farm prevalence of E. coli O157 was 37.8% (68 of 180 farms). The highest prevalence was found on dairy cattle farms (61.2%, 30 of 49 farms). The prevalences on beef, mixed dairy and beef, and veal calf farms were 22.7% (17 of 75 farms), 44.4% (20 of 45 farms), and 9.1% (1 of 11 farms), respectively. A significant positive correlation between age category and E. coli O157 prevalence was found only on mixed dairy and beef farms and dairy farms. No influence of farm size or introduction of new animals was demonstrated.

Estimation of Listeria monocytogenes and Escherichia coli O157:H7 Prevalence and Levels in Naturally Contaminated Rocket and Cucumber Samples by Deterministic and Stochastic Approaches

2015 ◽  
Vol 78 (2) ◽  
pp. 311-322 ◽  
Author(s):  
AGNI HADJILOUKA ◽  
KYRIAKI-SOFIA MANTZOURANI ◽  
ANASTASIA KATSAROU ◽  
MARINA CAVAIUOLO ◽  
ANTONIO FERRANTE ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Culture Media ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Molecular Tests ◽  
The Media ◽  
High Level

The aims of the present study were to determine the prevalence and levels of Listeria monocytogenes and Escherichia coli O157:H7 in rocket and cucumber samples by deterministic (estimation of a single value) and stochastic (estimation of a range of values) approaches. In parallel, the chromogenic media commonly used for the recovery of these microorganisms were evaluated and compared, and the efficiency of an enzyme-linked immunosorbent assay (ELISA)-based protocol was validated. L. monocytogenes and E. coli O157:H7 were detected and enumerated using agar Listeria according to Ottaviani and Agosti plus RAPID'L.mono medium and Fluorocult plus sorbitol MacConkey medium with cefixime and tellurite in parallel, respectively. Identity was confirmed with biochemical and molecular tests and the ELISA. Performance indices of the media and the prevalence of both pathogens were estimated using Bayesian inference. In rocket, prevalence of both L. monocytogenes and E. coli O157:H7 was estimated at 7% (7 of 100 samples). In cucumber, prevalence was 6% (6 of 100 samples) and 3% (3 of 100 samples) for L. monocytogenes and E. coli O157:H7, respectively. The levels derived from the presence-absence data using Bayesian modeling were estimated at 0.12 CFU/25 g (0.06 to 0.20) and 0.09 CFU/25 g (0.04 to 0.170) for L. monocytogenes in rocket and cucumber samples, respectively. The corresponding values for E. coli O157:H7 were 0.59 CFU/25 g (0.43 to 0.78) and 1.78 CFU/25 g (1.38 to 2.24), respectively. The sensitivity and specificity of the culture media differed for rocket and cucumber samples. The ELISA technique had a high level of cross-reactivity. Parallel testing with at least two culture media was required to achieve a reliable result for L. monocytogenes or E. coli O157:H7 prevalence in rocket and cucumber samples.

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