Table 1.
Dates, sources and numbers of samples tested for prevalence of mcr-1 in GB
| Date and project type | Sample origin and location | Number of pig herds represented in the sample |
Number of archived E. coli isolates | Number of colistin- resistant isolates | Number of mcr-1- positive herds | Herd prevalence (95% CI) | |
|---|---|---|---|---|---|---|---|
| healthy | diseased/veterinary diagnostic | ||||||
| 2013 surveillance | abattoir, UK | 115 | – | 190a | – | 0 | 0% (–) |
| 2014–15 research project | abattoir, England | 57 | – | 556b | 63 | 0g | 0% (–) |
| 2015 surveillance | abattoir, GB | 313c | – | 200d | 0e | 0% (–) | |
| NAc | 204f | 2g | 0.6% (0%–1.5%) | ||||
| 2015/16 veterinary diagnostic submissions | veterinary, England and Wales | – | 105 | 163h | 4 | 2g | 1.9% (0.0%–4.5%) |
NA, not applicable.
ESBL-producing E. coli recovered from porcine caecal samples from a UK-wide surveillance project20 for which WGS was available.
E. coli cultured from randomly selected porcine caecal samples collected from England.
387 randomly selected porcine caecal samples originating from 313 different pig herds in GB as part of an EU-wide surveillance programme.
E. coli recovered from MacConkey plates without colistin from these porcine caecal samples.
Isolates tested by PCR for mcr-1.
E. coli recovered on selective MacConkey plates containing 2 mg/L colistin following overnight enrichment.
Isolates tested by RT–PCR for mcr-1.
E. coli recovered from clinical submissions from diseased animals in England and Wales.