Table 2.

Association of prior colistin exposure with phenotypic colistin susceptibility and mcr carriage in poultry- and native-chicken isolates.

Origin of isolates	Prior colistin exposure (N)	Phenotypic colistin susceptibility, number (%)			Carriage of mcr gene, number (%)
		Sensitive	Resistant	p value	Yes	No	p value
Poultry-chicken faeces	Yes (61)	14 (23.0)	47 (77.0)	0.002	28 (45.9)	33 (54.1)	0.018
	No (38)	21 (55.3)	17 (44.7)		8 (21.1)	30 (78.9)
Native-chicken faeces	Yes (10)	2 (20.0)	8 (80.0)	0.154	5 (50.0)	5 (50.0)	0.018
	No (40)	20 (50.0)	20 (50.0)		5 (12.5)	35 (87.5)
Combined	Yes (71)	16 (22.5)	55 (77.5)	0.000	33 (46.5)	38(53.5)	0.000
	No (78)	41 (52.6)	37 (47.4)		13 (16.7)	65 (83.3)