Question

Patient is a 43 year old female with a history of Tetrad Fallot and mitral valve prolapse • Admitted to hospital with chief complaint of intermittant fevers, weight loss, fatigue and headaches for the past 3 months • Had dental surgery 4 months ago but there were no complications appearing after that surgery and she was not given any antibiotics

• Further data on patient Ms. "X": • Small skin lesions and hemorrhages in the nail beds • Blood cultures grew Gram positive cocci in chains from all four blood culture bottles taken
What is the likely source of this organism?
A. Environment (dust, soil, water)
B. Dental instruments
C. Skin
D. Patients own mouth - saliva
E. Urinary tract

Answer 1

The likely source of the organism in this case is the patient's own mouth - saliva (D). Bacterial endocarditis, an infection of the heart valves, can occur when bacteria from the mouth enters the bloodstream through a cut or injury in the gums. In this case, the patient's gum was nicked during dental surgery, allowing Streptococcus bacteria to enter the bloodstream.

Step-by-step explanation:

The likely source of the organism in this case is the patient's own mouth - saliva (D).

Given the patient's history of Tetralogy of Fallot and mitral valve prolapse, it is likely that she has an underlying heart condition which puts her at risk for bacterial endocarditis. Bacterial endocarditis is an infection of the heart valves, and one common route of entry for bacteria into the bloodstream is through the mouth.

During the dental surgery 4 months ago, the patient's gum was nicked with a sharp instrument, allowing the bacterium Streptococcus, which is normally present in the mouth, to gain access to the bloodstream. The presence of Gram positive cocci in chains in the blood cultures is consistent with Streptococcus infection.