Table 1 Numbers of essential genes under laboratory conditions in relevant E. coli , S. Typhimurium and S. Typhi isolates

E. coli

K-12 MG1655

302/4477

Published literature and MD (medium-scale) and LD (large-scale) deletion mutants (targeted mutagenesis, antibiotic medium 3)

Profiling of E. coli chromosome (PEC) database (http://shigen.lab.nig.ac.jp/ECOli/pec/)[9, 10]

E. coli

K-12 BW25113

303/3985

Single-gene deletion mutants (targeted mutagenesis, LB)

Keio collection[7]

E. coli

K-12 BW25113

299/3864

Single-gene deletion mutants (targeted mutagenesis, LB)

Update on the Keio collection[8]

E. coli

K-12 W3110

299/4109

Published literature

PEC database (http://shigen.lab.nig.ac.jp/ECOli/pec/)[9, 10]

S. Typhimurium

ATCC 14028

NA/1,023

Single-gene deletion mutants (targeted mutagenesis, LB)

[4]

S. Typhimurium

ATCC 14028

257/NA

Insertion-duplication mutagenesis (IDM) sequencing (random mutagenesis, LB)

[5]

S. Typhimurium

LT2

144 (LB and/or M9/glc)/NA

Metabolic reconstruction (in silico approach, M9/glc and LB)

[6]

S. Typhi

Ty2 (STY2)

356/4162

Random transposon mutagenesis and two types of growth^a

[3]