A 36-year-old man presents with focal central nervous system signs. Imaging shows a brain abscess. The dominant organism is an anaerobe normally found as part of the oral flora. Which of the following best fits that description?

A 23-year-old man who has recently started working on a sheep farm in Nova Scotia develops pneumonia shortly after helping with lambing. His cough produces little sputum, and a saline-induced sputum sample shows no predominant organism either with Gram stain or with acid-fast stain. It is established that he acquired the pneumonia from parturition products from the sheep. Which agent is most likely to be the cause of his pneumonia?

A 3-year-old girl presents with difficulty breathing and will not lie down to be examined. You suspect acute bacterial epiglottitis and examine the child's epiglottis, which is highly inflamed. Which vaccine are you most likely to find that the child is missing?