2 of 4 innoculums are growing

Campylobacter is exactly a sort of "difficult cultures". Not all of them are growing even innoculate on freshly-made and supplement-added agar plate. Seem I have to optimise their incubating condition such as temperature (37˚C -> 42˚C) and atmosphere (CO2 7.5% -> 10% or even 20%). You fastidious bugs...!!