This is the 14051st most frequent Turkish word.
mikroba
The Turkish word "mikroba" is not a standard form. If you mean "mikrop," it translates to "microbe" or "germ" in English.
Here, 'mikroba' (to the microbe/germ) is used in a dative case referring to 'against germs' in context of immunity development.
Mikroba karşı bağışıklık geliştirmek önemlidir.
Developing immunity against germs is important.
In this sentence, 'mikroba' relates to the agent (germ) from which protection is sought and is used in the dative case indicating the direction or recipient of the action.
Ellerimizi yıkayarak mikroba karşı korunabiliriz.
We can protect ourselves against germs by washing our hands.
Here, 'mikroba' is used to specify 'to the germ' directionality of the treatment application, explained through its dative usage.