1. Presented by Rebecca Wingfield, M.D. and reviewed by Andrew Clark, Ph.D.

A patient with past medical history of idiopathic bronchiectasis/centrilobular nodularity, recurrent sinusitis, and recurrent pneumonia presented with several days of increased cough productive of green mucus.  They were recently seen by dermatology with concerns of a nail infection; physical exam demonstrated yellow discoloration with separation of the nail plate from the nail bed.

Expectorated sputum demonstrated heavy polymorphonuclear leukocytes, very light squamous epithelial cells, and mixed respiratory flora on Gram stain. An organism grew out on sheep blood and chocolate agars but did not grow on MacConkey agar. The organism was identified by MALDI-TOF mass spectrometry as Pasteurella multocida.

What is the most likely source of infection?