A compound of the formula:
wherein
X is —N═, —CH═, or the like;
W is —CH
2
— or the like;
U is —S— or the like;
R
1
and R
2
are each independently hydrogen, halogen, optionally substituted lower alkyl, or the like;
Q is a single bond or the like;
R
3
is hydrogen or the like;
Ring A is a 6-membered aromatic heterocyclic group having 1-3 nitrogen atoms;
each R
4
is independently hydrogen, halogen, or the like;
m is an integer from 0 to 2;
G is —C(═O)— or the like;
D is a single bond, —NH—, or the like; and
E is a cyclic quaternary ammonium group,
or an ester, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof.