Do the bacterial species X, Y, Z code for proteins A, B, C?
First of all, don't reinvent the wheel, search for annotated homologs first. Assuming you don't find them, the next step is:


Collect the sequences of your query proteins (not genes) from one species in a multifasta file. 
Run a tBLASTn with those sequences against the genomes of all the other species of interest. 
Analyze. Look for HSPs with a certain level of sequence identity. The details of what threshold you choose will depend on your data, I can't help you  there. 


While the tBLASTn approach is going to be more sensitive, an easier method that can find gene structures and not just HSPs is to use exonerate:

exonerate -m p2g proteins.fa genome.fa


Finally, for a more sensitive search than either of the above, useful for finding more distant homologs, run a Psi-tBLASTn of your proteins against the genomes of interest. 

In all of these approaches, the tricky bit is to choose the right threshold. Unfortunately, there is no golden rule here. It all depends on how closely related your species are and how similar the homologs. You will have to try a few different ones before you can choose the right one.