Table 1 Targets of positive selection. (a) Generally. (b) With respect to antibiotic resistance.

From: A genome-wide scan of wastewater E. coli for genes under positive selection: focusing on mechanisms of antibiotic resistance

(a) Positive selection targets different functions.

Function

Genes

Antibiotic resistance

yfaL, ycgV, lsrA, ydhQ, ompC, ompA, hipA, dgcE

Cellular response to DNA damage stimulus

btsT, yhaC, sbcC, uxuA

Cellular protein modification process

pphC, ptsP, def, ydiU

Establishment of protein localization to extracellular region

gspC, gspL, gspK, dtpD

Carbohydrate transport

agaC, ptsN, uidC, fruA

DNA dealkylation involved in DNA repair

alkA, alkB

DNA restriction-modification system

dcm, hsdS

tRNA wobble base modification

tilS, tmcA

Determination of cell shape

mreC

Essential for cell division

ftsK

Protein deubiquitination

elaD

Protein integration into the cell membrane

ynbB

Aromatic compounds biosynthesis

paaF, mhpA, cpdB, deaD

Folic acid biosynthesis

folk, abgB

Glyoxylate biosynthesis

glcB, icd

Lactose biosynthesis

lacZ

Lipoprotein biosynthesis

lnt

Amino acid activation for nonribosomal peptide biosynthesis

entF

Uroporphyrinogen III biosynthesis

hemD

Glycine betaine biosynthesis

betA

(b) The positively selected genes that are known to be involved in antibiotic resistance have different mechanisms of resistance.

Mechanism of antibiotic resistance

Genes

Biofilm formation

yfaL, ycgV, lsrA, ydhQ, dgcE

Outer membrane permeability

ompC, ompA

Efflux pumps

ompA

Bacterial persistence

hipA