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

Gautam R, Kulow M, Park D, Gonzales TK, Dahm J, Shiroda M, Stasic AJ, Döpfer D, Kaspar CW, Ivanek R - Epidemiol. Infect. (2014)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences,Texas A&M University,College Station, TX,USA.

ABSTRACT
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.

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Related in: MedlinePlus

Comparison of the percent survival of the three ECO157 strains (St1, St2,St3) in sterilized bovine faeces over time.
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fig02: Comparison of the percent survival of the three ECO157 strains (St1, St2,St3) in sterilized bovine faeces over time.

Mentions: The average number of c.f.u.s of St1, St2 and St3 infaeces over a 28-day storage period is shown in Table6 and the percent survival of each strain over time is presented in Figure 2. The growth of the three strains in LB wassimilar which resulted in essentially equal starting numbers of c.f.u.s (viable counts) atday 0, suggesting that the three strains have similar growth rates in the conditionstested. During the first 24 h post-inoculation in faeces, all three strains displayedaround a 1-log reduction in viable counts with an average percent survival of 22%, 13% and2%, respectively for St1, St2 and St3. After thisinitial decrease, the viable numbers of St1 remained relatively constantover the 28 days of incubation (2·54 × 106 c.f.u./g, 10% survivors). Bycontrast, St3 had the initial 1-log reduction followed by an additional3-log reduction in viable counts during the 28 days of incubation (7·43 × 103c.f.u./g, 0·01% survivors). The survival curve of St2 was in betweenthose of St1 (best survival) and St3 (poorest survival)and had a 3-log reduction during the 28 days of incubation (2·79 × 104c.f.u./g, 0·08% survivors). The mean decay rates estimated for St1, St2and St3 were 0·21, 0·26, 0·39, respectively. Nevertheless, the results ofthe repeated-measures ANOVA and comparison of decay rates did not confirm existence of asignificantly different survival in the three strains. Fig. 2.


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

Gautam R, Kulow M, Park D, Gonzales TK, Dahm J, Shiroda M, Stasic AJ, Döpfer D, Kaspar CW, Ivanek R - Epidemiol. Infect. (2014)

Comparison of the percent survival of the three ECO157 strains (St1, St2,St3) in sterilized bovine faeces over time.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4301210&req=5

fig02: Comparison of the percent survival of the three ECO157 strains (St1, St2,St3) in sterilized bovine faeces over time.
Mentions: The average number of c.f.u.s of St1, St2 and St3 infaeces over a 28-day storage period is shown in Table6 and the percent survival of each strain over time is presented in Figure 2. The growth of the three strains in LB wassimilar which resulted in essentially equal starting numbers of c.f.u.s (viable counts) atday 0, suggesting that the three strains have similar growth rates in the conditionstested. During the first 24 h post-inoculation in faeces, all three strains displayedaround a 1-log reduction in viable counts with an average percent survival of 22%, 13% and2%, respectively for St1, St2 and St3. After thisinitial decrease, the viable numbers of St1 remained relatively constantover the 28 days of incubation (2·54 × 106 c.f.u./g, 10% survivors). Bycontrast, St3 had the initial 1-log reduction followed by an additional3-log reduction in viable counts during the 28 days of incubation (7·43 × 103c.f.u./g, 0·01% survivors). The survival curve of St2 was in betweenthose of St1 (best survival) and St3 (poorest survival)and had a 3-log reduction during the 28 days of incubation (2·79 × 104c.f.u./g, 0·08% survivors). The mean decay rates estimated for St1, St2and St3 were 0·21, 0·26, 0·39, respectively. Nevertheless, the results ofthe repeated-measures ANOVA and comparison of decay rates did not confirm existence of asignificantly different survival in the three strains. Fig. 2.

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences,Texas A&M University,College Station, TX,USA.

ABSTRACT
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.

Show MeSH
Related in: MedlinePlus