Simplified code (highlighting doesn't apply here).

themes/bootstrap3/templates/RecordDriver/SolrDefault/list-entry.phtml

@@ -43,13 +43,8 @@
         <?=implode('<br>', array_map(array($this, 'escapeHtml'), $this->driver->getSummary())); ?>
       <? else: ?>
         <? $summAuthor = $this->driver->getPrimaryAuthor(); if (!empty($summAuthor)): ?>
-        <?=$this->transEsc('by')?>
-        <a href="<?=$this->record($this->driver)->getLink('author', $summAuthor)?>"><?
-          $summHighlightedAuthor = $this->driver->getHighlightedAuthor();
-          echo !empty($summHighlightedAuthor)
-              ? $this->highlight($summHighlightedAuthor)
-              : $this->escapeHtml($summAuthor);
-        ?></a>
+          <?=$this->transEsc('by')?>
+          <a href="<?=$this->record($this->driver)->getLink('author', $summAuthor)?>"><?=$this->escapeHtml($summAuthor)?></a>
         <? endif; ?>
 
         <? $journalTitle = $this->driver->getContainerTitle(); $summDate = $this->driver->getPublicationDates(); ?>