ZF2 - \ Zend \ Db \ Adapter \ Platform :: getQuoteIdentifierSymbol ()

The code is as follows, where I want to use Pdo_mysql:

use \Zend\Db\Adapter\Adapter;
use \Zend\Db\Sql\Sql;
use \Zend\Db\Sql\Expression;    

$params = array(
    'driver'   => "Pdo_mysql",
    'host'     => &$this->Registry->config[ 'sql' ][ 'host' ],
    'username' => &$this->Registry->config[ 'sql' ][ 'user' ],
    'password' => &$this->Registry->config[ 'sql' ][ 'passwd' ],
    'dbname'   => &$this->Registry->config[ 'sql' ][ 'dbname' ]
);
$this->adapter  = new \Zend\Db\Adapter\Adapter( $params );
$this->platform = $this->adapter->getPlatform();
$this->sql      = new Sql( $this->adapter );

And when I check the quote character with:

print $this->platform->getQuoteIdentifierSymbol();    // Output: "

As you can see, the double quote is a character. This, of course, invalidates all of my MySQL queries, as it quotes all identifier names (tables, columns, etc.) with double quotes (") instead of direct quotes (`).

So why does the PDO-MySQL driver use the Sql92 character instead? And how to fix it?