Droplet Transmission of Streptococcus sanguinis Causing Pyogenic Liver Abscess in a Male Patient With a Transplanted Liver.

Streptococcus sanguinis is abundantly present in the oral cavity and colonizes the enamel as a natural part of the microbiome. Through the formation of a healthy biofilm, this bacterium provides a protective role. However, under certain conditions, it has the ability to become pathogenic. A pyogenic liver abscess (PLA) occurs through the contiguous spread of infectious pathogens from neighboring structures or following a trauma. The isolation of S. sanguinis as the pathogen in liver abscesses has only been reported twice. Here, we report the third case of PLA caused by S. sanguinis occurring in a young adult male patient, with a transplanted liver, biliary stenosis, and external drain. The bacterium was isolated from blood cultures. The most likely route of the acquisition was droplet transmission of a family member during drain irrigation. The patient was treated successfully with antibiotics, and he fully recovered.