Can't load MediaGroups

[Sebastian Hernandez]

Hello People. Im tryng to load the info that comes from mediagroups and i haven't found the right way to do it.

The Code Im using is this: 

google.load("feeds", "1");

function initialize() {

      var feed = new google.feeds.Feed("http://gdata.youtube.com/feeds/api/playlists/DB-uUT9jNTg9wC6Cwa5ufO1yegAHwUqa");

 feed.setNumEntries(8);

      feed.load(function(result) { 

for (var i = 0; i < result.feed.entries.length; i++) {

            var entry = result.feed.entries[i];

 $("#feed").append(entry.title + "<br>" + entry.link + "<br>" + entry.publishedDate + "<br>"  + entry.mediaGroups[0].description + "<br>")

}

     

          }

 

      );

    }

    google.setOnLoadCallback(initialize);

When i take out the mediaGroups part of the code, it show the link, title and publishdate succesfully but when i use mediagroups it doesnt appear anything... Thanks for the help!