Klebsiella bacteria have also developed a high level of resistance to antibiotics, such as <a href="http://www.cdc.gov/hai/organisms/cre/index.html" target="_blank" target="_blank">carbapenem</a>. The bacteria naturally occurs in the intestines where it does not usually cause disease, but it can cause pneumonia, bloodstream infections and meningitis.<br /><br />It's unlikely that healthy people are affected by the bacteria, but <a href="http://www.cdc.gov/HAI/organisms/klebsiella/klebsiella.html" target="_blank" target="_blank">patients in hospitals</a> who use a ventilator, intravenous catheters or long courses of certain antibiotics are at higher risk of becoming infected. 