I do not want to use .htaccess. How should I change my Directory attributes?
ServerName abc.com
DocumentRoot /usr/share/uploads
The easiest way would be to put an empty index.html (or whatever you apache is configured to deliver by default) inside that directory. This is not a real solution but a very simple workaround. The user browsing that directory would just see a blank white page.
Further you could use a script (like index.php) wich emulates the directory-listing and only shows some special files.