  In the model of low-energy bar-K N interactions near threshold (EPJA 21, 11
(2004); 25, 79 (2005)) we calculate isospin-breaking corrections to the energy
level displacement of the ground state of kaonic hydrogen, investigated by
Meissner, Raha and Rusetsky (EPJC 35, 349 (2004)) within the non-relativistic
effective Lagrangian approach based on ChPT by Gasser and Leutwyler. Our
results agree well with those by Mei\ss ner et al.. In addition we calculate
the dispersive corrections, caused by the transition K^-p -> bar-K^0n ->K^-p
with the bar-K^0n pair on-mass shell. We show also how hypothesis on the
dominant role of the bar-K^0n-cusp for the S-wave amplitude of low-energy K^-p
scattering near threshold, used by Meissner et al., can be realized in our
approach. The result agrees fully with that by Meissner et al..
