Table 1. Prevalence of resistance to ceftriaxone, meropenem, or colistin; of ESBL production; and, of the presence of the mcr-1 gene in Enterobacteriaceae isolated from pregnant sows.

Pregnant sows within 30 days before parturition
Antibiotic resistance and presence of ESBL and mcr-1 gene	Farm A (N = 12)	Farm B (N = 6)
Ceftriaxone-resistant Enterobacteriaceae	12 (100%)	6 (100%)
ESBL-producing Enterobacteriaceae	12 (100%)	6 (100%)
Meropenem-resistant Enterobacteriaceae	0 (0.0%)	0 (0.0%)
Colistin-resistant Enterobacteriaceae	0 (0.0%)	0 (0.0%)
Presence of mcr-1 gene in colistin-resistant Enterobacteriaceae	N/A	N/A

Abbreviations: ESBL, extended spectrum beta-lactamase; mcr-1 gene, mobilized plasmid-borne colistin resistance gene; N/A, not applicable.