Bacterial infections come in many forms. Although most forms are not fatal for us, there are some though that can literally kill within days after infection. The truth is that bacterial infections have been a bane for past civilizations as there have been many who succumbed to the disease. If you are familiar with the Black Death or Bubonic Plague that decimated many areas of Europe during the Middle Ages, the cause of the infection is called Yersinia pestis, a type of bacterium carried by black rats. Although the disease is no longer rampant today, if it ever goes rampant, it can be effectively treated using antibiotics like metronidazole.