Other bacterial features important for identification and virulence: capsule

• acidic polysaccharides forming slimy outer layer

• capsule blocks phagocytosis

• Klebsiella pneumoniae has a very sticky polysacharride capsule

ID by capsular type: Haemophilus influenzae B

• kids all get the HIB vaccine

• HIB used to be the most common cause of meningitis in kids

• 15 years ago, the average age of a patient with meningitis was 10

• now, it’s 25; meningitis is an adult disease, and that’s because of this vaccine

• immunity against just the capsule prevented the disease

• it’s coccobacillus, meaning sometimes it’s round and sometimes it’s rodlike

• hard organism to grow in culture: requires different factors in blood

• development of vaccine has virtually eradicated hemophilus meningitis in the US

Category: Microbiology Notes