Twitter Steaming API and Nodejs - Unauthorized access

I am using the following code to access twitter streaming api with nodejs:

var https = require('https');   
var options = {   
   host : 'stream.twitter.com',
   path : '1.1/statuses/sample.json',   
   method : 'GET',  
   headers : {   
   "Authorization": "Basic "+new Buffer("username:password").toString("base64")
 }   
};
var request = https.request(options,function(response){   
var body = '';
response.on("data",function(chunk){    

console.log(chunk.toString("utf8"));

var tweet = JSON.parse(chunk);  
console.log(tweet.text);  
});  
});  
request.end();

I already tested the username and password being used. Working fine.

When I print the chunk, I get the following

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>Error 401 Unauthorized</title>
</head>
<body>
<h2>HTTP ERROR: 401</h2>
<p>Problem accessing '1.1/statuses/sample.json'. Reason:
<pre>    Unauthorized</pre>
</body>
</html>

Appreciate your assistance.

Regards