not able to connect to mongodb hosted on remote server using monk

Question

I am using node js, and for the backend i am using mongodb

For connecting to DB, if i use the below line, it is fetching data

var db = monk('localhost:27017/nodetest2');

But if i change that to below line, its not fetching the data

var db = monk('mongodb://username:password@XXX.mongolab.com:27483/userdb');

I have created the collection with same name in both places

router.get('/userlist', function (req, res) {
    var db = req.db;
    var collection = db.get('userlist');
    collection.find({}, {}, function (e, docs) {
        res.json(docs);
    });
});