Resistance to Penicillin in Staphylococcus aureus from Dairy Cows
Author Information
Author(s): Bennedsgaard Torben W, Thamsborg Stig M, Aarestrup Frank M, Enevoldsen Carsten, Vaarst Mette, Christoffersen Anna B
Primary Institution: Danish Institute for Agricultural Sciences
Hypothesis
What is the prevalence of Staphylococcus aureus and penicillin-resistant Staphylococcus aureus in conventional and organic dairy herds in Denmark?
Conclusion
The prevalence of penicillin resistance among Staphylococcus aureus isolates in Danish dairy herds is low, making penicillin a suitable treatment option.
Supporting Evidence
- The overall prevalence of Staphylococcus aureus was 29% among high-risk cows.
- The prevalence of penicillin resistance among Staphylococcus aureus infected cows was 12%.
- No significant differences in penicillin resistance were found between herd groups.
Takeaway
This study looked at cows in Denmark to see how many had a type of bacteria that doesn't get killed by penicillin. They found that not many cows had this problem.
Methodology
Quarter milk samples were collected from cows with high somatic cell counts in various dairy herds, and the prevalence of Staphylococcus aureus and its penicillin-resistant strains was analyzed.
Potential Biases
The prevalence estimates may be biased due to the dominance of a few clones of Staphylococcus aureus in herds.
Limitations
The study's sample scheme may not accurately estimate the prevalence of infection among cows with low infection risk.
Participant Demographics
Cows from 20 conventional herds, 18 organic herds converted before 1995, and 19 herds converting to organic farming in 1999 or 2000.
Statistical Information
P-Value
0.03
Confidence Interval
95% confidence interval: 24%–34%
Statistical Significance
p=0.03
Digital Object Identifier (DOI)
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