  Using integral field data we extract the optical spectra of shocked
interstellar clouds in Kepler's supernova remnant located in the inner regions
of our Galaxy, as well as in the Large Magellanic Cloud (LMC), the Small
Magellanic Cloud (SMC), NGC6822 and IC 1613. Using self-consistent shock
modelling, we make a new determination of the chemical composition of the
interstellar medium (ISM) in N, O, Ne, S, Cl and Ar in these galaxies and
obtain accurate estimates of the fraction of refractory grains destroyed in the
shock. By comparing our derived abundances with those obtained in recent works
using observations of B stars, F supergiant stars and HII regions, we provide a
new calibration for abundance scaling in the range $7.9 \lesssim 12+\log
{\mathrm {O/H}} \lesssim 9.1$.
