Case Presentation: A 43 year old male to female transgender patient with a history of AIDS on HAART, ESRD on hemodialysis, pulmonary embolism, heart failure with reduced ejection fraction with AICD in place, history of recurrent ventricular and supraventricular tachycardia with prior ablation presented to our hospital reporting dizziness and several episodes of non-bloody non-bilious vomiting with decreased appetite since the past few days. She lived with her therapy dog, with no recent travel history, and no exposure to farm animals. She was found to have supraventricular tachycardia which terminated with adenosine. She was afebrile with a heart rate of 123 and BP of 124/89 and saturating 96% on room air. Initial exam was notable for tachypnea without accessory muscle use and tachycardia with a regular rhythm. Labs were remarkable for a high anion gap metabolic acidosis with a lactate of 9, BUN and Creatinine of 56 and 9.2 respectively. She was admitted to the telemetry service for pre – syncope likely due to the SVTs. Chest x-ray showed interstitial opacities.
Blood culture obtained grew gram negative bacilli and ID were consulted. She was started on levofloxacin and meropenem to cover for hospital acquired pneumonia versus zoonosis due to bordatella, legionella, brucella, actinobacillus, campylobacter, francisella, helicobacter, pasteurella given that her therapy dog was with her even in hospital. The gram negative bacilli were not growing on MacConkey or Chocolate plates, and could not be identified by the microbiology lab. The organism was sensitive to levaquin, and the patient was eventually discharged on the latter. The specimen was sent to the department of health, where the organism was identified as Bergeyella zoohelcum. The therapy dog although never bit the patient, always slept with her and licked her including her AV access.
Discussion: Bergeyella zoohelcum is a gram negative rod that is part of the normal oral microbiota from cats, dogs and other animals such as piglets. Identification is challenging and there have been cases of misidentification. It is a non-fermentative bacilli but differs from others in being susceptible to penicillin.
Most of the reported cases have been related to bites from dogs, cats, Siberian tiger or contact with these animals. Some colonies have been isolated frequently during routine analyses of food, therefore oral transmission can be possible.
Commonly reported infections with B. zoohelcum include cellulitis, abscesses, diarrhea, lymphangitis, endocarditis, bacteremia, pneumonia, tenosynovitis and bed sore infection. This is the first case reported of B. zoohelcum infection in a patient with AIDS. In this case there was no bite but contact with a dog.
B. zoohelcum has shown to be susceptible to β-lactam antibiotics, including penicillin. In all of the reported cases treatment was curative, medications used include: penicillin, oxacillin, amoxicillin – clavulanate, ampicillin- sulbactam, cephalosporins, ciprofloxacin and in our case levofloxacin and meropenem.
Conclusions: Bergeyella zoohelcum is a rare cause of bacteremia usually seen in patients exposed to cats and dogs. The role of immunosuppression and chronic illness is not well established. Physicians should suspect this pathogen in patients with gram negative bacilli bacteremia with history of exposure to these animals especially if regular cultures do not provide identification. Amoxicillin clavulanate and ampicillin sulbactam seem to be an effective initial approach in patients with history of animal bites.