ISM properties in low-metallicity environments

We present new ISOCAM mid-infrared spectra of three starbursting nearby dwarf galaxies, NGC$\;$1569, NGC$\;$1140 and II$\;$Zw$\;$40 and the 30$\;$Dor region of the LMC and explore the properties of the ISM in low-metallicity environments, also using additional sources from the literature. We analyse the various components of the ISM probed by the mid-infrared observations and compare them with other Galactic and extragalactic objects. The MIR spectra of the low-metallicity starburst sources are dominated by the [ Ne ii