Index: wp-admin/network/themes.php
===================================================================
--- wp-admin/network/themes.php	(revision 36734)
+++ wp-admin/network/themes.php	(working copy)
@@ -143,8 +143,12 @@
 					<ul class="ul-disc">
 					<?php
 						foreach ( $theme_info as $theme ) {
-							/* translators: 1: theme name, 2: theme author */
-							echo '<li>', sprintf( __('<strong>%1$s</strong> by <em>%2$s</em>' ), $theme->display('Name'), $theme->display('Author') ), '</li>';
+							echo '<li>' . sprintf(
+								/* translators: 1: theme name, 2: theme author */
+								__( '%1$s by %2$s' ),
+								'<strong>' . $theme->display('Name') . '</strong>',
+								'<em>' . $theme->display('Author') . '</em>'
+							) . '</li>';
 						}
 					?>
 					</ul>