C-184. Man’s Best Friend as the Source of β-Lactamase Producing Pasteurella multocida: The Cause of Pneumonia and Bacteremia in a 74-Year-Old Man

H. Namdari1, K. Jacobs2, K. Pidcock3, D. Kosinski2, J. Sibai2;
1Clin-Micro Immunology Ctr., Scranton, PA, 2Mercy Hosp., Scranton, PA, 3Wilkes Univ., Wilkes Barre, PA.

Background: Pasteurella multocida is a zoonotic agent colonizing the mucus membranes of the upper respiratory tract of wild and domesticated animals, especially dogs and cats. Human infections with P. multocida usually occur through direct animal bites or close contacts. We describe the case of a 74 year-old man who presented to the ER with dizziness, increased fatigue, and cough productive of yellowish sputum. His past history revealed hospitalization and treatment for pneumonia in another institution 4 months earlier, without remittance of productive cough. CT scan of the chest showed bilateral lower lobe infiltrates with a suspicious mass, COPD changes, and mucous plugging in the left lower bronchi. The patient was admitted, and began treatment with oral levofloxacin (750 mg daily) after collection of blood and sputum specimens for bacterial evaluation. Methods: Sputum Gram stain was preformed and inoculated on 5% sheep blood agar, MacConkey agar and chocolate agar (Remel). Blood culture bottles were placed in a BACTEC-240 blood culture machine (BD). Both sputum and blood isolates were identified through rapid ID NH (Remel) and conventional systems. Antibacterial susceptibility was tested by broth microdilution on a MicroScan experimental Gram Negative panel (Siemens). Results: The sputum Gram stain showed many neutrophils and gram negative coccobacilli. Both the patient’s blood and sputum cultures grew P. multocida. Because the patient was a dog owner, the dog’s mouth was swabbed and P. multocida was recovered from the dog. The organisms were cefinase positive and resistant to ampicillin, cefotetan, cefotaxime, meropenem, and intermediately resistant to cefepime with MICs of >16, >32, >32, >8, and 16, respectively. Both respiratory and blood isolates were susceptible to levofloxacin. All isolates from patient’s blood, sputum, and dog’s mouth were examined by Pulsed-Field Gel Electerophoresis using Apal digest appeared identical. The patient was successfully treated with continued oral levofloxacin therapy. Conclusions: This report indicates that pet dogs can serve as a risk factor for serious life threatening systemic human infections with β-lactams resistant P. multocida.