Why the discovery of adherent-invasive Escherichia coli molecular markers is so challenging?

Table 5 Comparison of the principal experimental conditions of the protocols used to assess bacterial invasion to intestinal epithelial cells and survival and replication inside macrophages

Invasion assays
MOI	Infection conditions	Incubation conditions	Ref.
10	30 min	3 h with amikacin 100 µg/mL	[13]
10	1 h	2 h with gentamicin 100 µg/mL	[70]
10 or 20	3 h	1 h with gentamicin 100 µg/mL	[1,9,11,14,16,31,34,47,56-60,63-65,71]
10	3 h	1 h with gentamicin 3 mg/mL	[72]
100	2 h	1 h with gentamicin 50 µg/mL	[54]
100	3 h	1 h with gentamicin 50 µg/mL	[62]
Survival and replication assays
10	20 min	Media replacement with gentamicin 100 µg/mL for 40 min and media replacement with gentamicin 50 µg/mL for 24 h	[16]
10	2 h	Media replacement with amikacin 100 µg/mL for 3 and 24 h	[13]
10	2 h	Media replacement with gentamicin 100 µg/mL for 1 h and media replacement with gentamicin 20 µg/mL for 24 h	[1,34,58]
10 or 100	Centrifugation 10 min at 1000 g and incubation 10 min	Media replacement with gentamicin 100 µg/mL for 40 min and media replacement with gentamicin 20 µg/mL for 24 h	[11,47,66]
10	Centrifugation 5 min at 500 g and incubation 30 min	Media replacement with gentamicin 100 µg/mL for 2 h and media replacement with gentamicin 15 µg/mL for 24 h	[70]
20	2 h	Media replacement with gentamicin 100 µg/mL for 1 h and media replacement with gentamicin 20 µg/mL for 24 h	[9,31]
20	2 h	Media replacement with gentamicin 100 µg/mL for 1 and 24 h	[14]
20	2 h	Media replacement with gentamicin 3 mg/mL for 1 and 24 h	[72]
100	Centrifugation 10 min at 1000 g and incubation 10 min	Media replacement with gentamicin 20 µg/mL for 1 and 24 h	[21,59]
100	2 h	Media replacement with gentamicin 50 µg/mL for 1 and 24 h	[54]