Error running blastdbaliastool

[nupurgupta]

SOLVED: The makedb tool was not creating index files. I directly downloaded the database from NCBI and it is working.

Hi,
I am running command line blastplus, and need to blast against bacteria. I have downloaded databases nr and nt, but need to create a subset for faster searching. I have followed the method in

http://www.biostars.org/post/show/6528/vertebrate-subset-nr-database-build-my-own/

where I have downloaded a list of accession numbers for bacteria, and am trying to create a subset database based on this. I have tried the command

blastdb_aliastool -gilist bacteria.gilist.txt -db nr -out nr_bacter -title nr_bacteria
but I get an error
"BLAST Database error: GI list specified but no ISAM file found for GI."

Any idea what this is?
Thanks so much