Table 7. Herd-level evaluation of the association between season and isolation of at least one Salmonella resistant to the referred antimicrobial drug from a farm during a sampling visit.
| Season1 | Ceftriaxone | Ciprofloxacin | Tetracycline | Ampicillin | MDR* | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| %2 | OR3 [95% CI] | P-value4 | %2 | OR3 [95% CI] | P-value4 | %2 | OR3 [95% CI] | P-value4 | %2 | OR3 [95% CI] | P-value4 | %2 | OR3 [95% CI] | P-value4 | |
| Winter | 12 | 4.3 [1.3–14.4] | 0.014 | 2 | 0.3 [0.05–2.4] | 0.23 | 16 | 2.6 [0.8–7.7] | 0.07 | 10 | 1.0 [0.3–3.2] | 0.88 | 12 | 2.5 [0.8–7.7] | 0.10 |
| Spring | 3 | 0.6 [0.1–2.8] | 0.50 | 9 | 13.6 [2.9–62.4] | 0.0005 | 9 | 1.3 [0.4–4.2] | 0.66 | 9 | 1.8 [0.5–5.9) | 0.33 | 9 | 2.7 [0.8–9.1] | 0.11 |
| Summer | 8 | 1.8 [0.5–6.2] | 0.35 | 0 | – | – | 8 | 0.5 [0.2–1.8] | 0.33 | 8 | 0.8 [0.2–2.5] | 0.68 | 8 | 1.1 [0.3–3.8] | 0.80 |
| Fall | 0 | – | – | 3 | 0.6 [0.1–3.3] | 0.59 | 8 | 0.5 [0.1–1.5] | 0.21 | 8 | 0.7 [0.2–2.1] | 0.53 | 0 | – | – |
Notes:
P-values in bold indicates a significant difference was observed.
Analysis was conducted using weighted Chi-square.
Season evaluated.
Survey adjusted percent of farms for which at least one fecal sample cultured positive for a Salmonella with resistant to the referred antimicrobial during one of the four season samplings.
Odds ratio for culturing at least one Salmonella resistant at the herd to the referred drug for herd with the referred season when compared to any other season.
P-value for the odds ratio.
Salmonella isolates identified as multidrug resistant.
During the referred season either no animals with a culture positive for a Salmonella resistant to the referred drugs was isolated, or no animals with a culture negative fecal sample for Salmonella or a culture positive sample for salmonella that is susceptible to the referred antimicrobial drug. Therefore effect of season could not be evaluated.