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A5454 - A Case of Necrotizing Pneumonia: Community Acquired Multi-Drug Resistant Pseudomonas Infection?
Author Block: P. Sharma, I. Romero; PCCM, UTHSC, Memphis, TN, United States.
Pseudomonas aeruginosa is an uncommon cause of community-acquired pneumonia (CAP) in immunocompetent hosts. It is mostly seen in patients with structural lung abnormality such as cystic fibrosis or in immunocompromised hosts. Drug resistant pseudomonas infection in CAP is very rare.
A 57-year-old African American male with past medical history significant for well controlled Diabetes Mellitus and HTN presented to hospital with generalized weakness for 2-3 weeks duration and diarrhea for 5 days. He reports low grade fever, loss of appetite, night sweats, and weight loss but no cough or any sputum production. He is not on any immunosuppressive drugs. He denied recent travel, hospital admission, or sick contacts. He is a non-smoker, no occupational exposure for pulmonary disease. Patient was admitted to floor and treated for CAP. Infectious disease team was consulted three days later for antibiotics recommendation as patient had poor response to initial antibiotics. The coverage was broadened to Linezolid and Cefepime based on cavitation noted on CT chest. Pulmonary service was consulted a week later as his cavitary pneumonia was getting worse on repeat CT chest and had persistent leukocytosis.
On examination, his vital signs were normal and was comfortable on room air. The complete physical examination was within the normal limits except for decreased air entry on LUL and crepitation on the left anterior chest.
Chest x-ray at presentation was suggestive of pneumonia on Left upper lobe (LUL). CT chest without contrast three days later showed LUL cavitary lesion. CT scan repeated a week later while on Linezolid, and Cefepime showed worsening of the cavity.
Urinary Legionella antigen at presentation was negative. We evaluated him with fiber optic bronchoscopy and was found to have a narrowing of apical and posterior segment of LUL, significant amount of purulent discharge was noted. Bronchial washing, BAL and endobronchial biopsy was obtained. Micafungin was added to the treatment regimen while awaiting the culture report. BAL culture was reported with Pseudomonas aeruginosa resistant to Cefepime and Ceftazidime but sensitive to Imipenem and Ciprofloxacin. BAL staining for acid-fast bacillus was negative. Antibiotic was switched to Meropenem, micafungin discontinued. Patient had gradual improvement in his symptoms. Leukocytosis resolved. The final results of mycobacterial and fungal cultures were negative.
This case highlights the possibility of resistant pseudomonas infection in a patient without significant risk factor. It also emphasizes the importance of bronchoscopy and BAL when pneumonia is not improved with typical antibiotics.