Case of eschfrichia coli necrotizing pneumonia with cavitary lesions

SESSION TITLE: Unusual PneumoniasSESSION TYPE: Rapid Fire Case ReportsPRESENTED ON: 10/19/2022 12:45 pm - 1:45 pmINTRODUCTION: Necrotizing pneumonia (NP) is a severe form of community acquired pneumonia which carries a high mortality rate. Escherichia coli (e. coli) infection is a rare cause of pneumonia [1]. However, more cases of e. coli pneumonia have been reported recently [2]. We present a case of a middle aged man with severe necrotizing pneumonia due to e. coli infection.CASE PRESENTATION: A 55-year-old current smoker male with history of polysubstance use disorder was brought to the emergency department from a detoxification program after being found down seizing. He was febrile, hypotensive, tachycardic and hypoxic on presentation. Patient was intubated for airway protection from post-ictal state. Initial lab work was remarkable for rhabdomyolysis, acute kidney injury, mildly elevated aminotransferases, and leukocytosis with bandemia. Computed tomography (CT) of the thorax showed a 7.5 x 7.7 x 8.9 cm cavitating lesion with thick irregular walls in the right lung, 2.5 x 2.8 x 2 cm cavitary lesion with a second smaller cavitating lesion in the left lower lobe; bronchiectasis, dense consolidation, and air bronchograms. Patient was placed on piperacillin/ tazobactam (Zosyn) and vancomycin. Sputum cultures from tracheal aspirate grew pansensitive e. coli. Micafungin was also started when beta-D-glucan was noted to be mildly elevated. Serial acid-fast bacterial (AFB) sputum cultures, and QuantiFERON-TB Gold were negative. Bronchoalveolar lavage (BAL) samples were also negative for malignant cells, and fungal cultures/AFB smears. Transthoracic echocardiogram showed no signs of vegetation.Repeat CT thorax on day 11 showed new 10 mm left upper lobe nodule with persistent cavitary lesions which prompted addition of inhaled tobramycin, switch Zosyn to cefepime, and change of micafungin to amphotericin B until histoplasma antibodies and Aspergillus galactomannan testing returned negative. Patient clinically improved and was extubated after 22 days on the ventilator.DISCUSSION: In our case, e. coli was identified in the first set of sputum cultures, with negative microbiological workup for the rest of the patient's hospitalisation. The mechanism of e. coli NP is unclear but may be a result of microaspiration of upper airway secretions colonised with e. coli with underlying diseases like diabetes mellitus and alcoholism [3]. Incidence of NP is rare and management can be challenging due to lack of guidelines. Intravenous antibiotic therapy remains the mainstay treatment of NP and pulmonary resection is reserved for patients who do not respond to antibiotic therapy or develop parenchymal complications of pulmonary gangrene [1].CONCLUSIONS: NP can have a prolonged clinical course with increased morbidity. E. coli is an emerging causative organism for NP and should be considered in differential diagnosis. Though work-up is warranted to ensure isolation and treatment of the appropriate organisms.Reference #1: Krutikov, M et al. "Necrotizing pneumonia (aetiology, clinical features and management).” Current Opinion in Pulmonary Medicine vol 25 (3) 225-32. May 2019, doi: 10.1097/MCP.0000000000000571Reference #2: Harsha, N S et al. "A rare cause of cavitatory pneumonia.” Respiratory medicine case reports vol. 19 125-7. 27 Aug. 2016, doi:10.1016/j.rmcr.2016.08.011Reference #3: Puri, M M et al. "Pneumatocele formation in adult Escherichia coli pneumonia.” Annals of thoracic medicine vol. 6,2 (2011): 101-2. doi:10.4103/1817-1737.78434DISCLOSURES: no disclosure on file for Shoaib Ahmad;No relevant relationships by Nasir AlhamdanNo relevant relationships by Rishabh BansalNo relevant relationships by Abira UsmanNo relevant relationships by Vishruth VyataNo relevant relationships by Ashley White SESSION TITLE: Unusual Pneumonias SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/19/2022 12:45 pm - 1:45 pm INTRODUCTION: Necrotizing pneumonia (NP) is a severe form of community acquired pneumonia which carries a high mortality rate. Escherichia coli (e. coli) infection is a rare cause of pneumonia [1]. However, more cases of e. coli pneumonia have been reported recently [2]. We present a case of a middle aged man with severe necrotizing pneumonia due to e. coli infection. CASE PRESENTATION: A 55-year-old current smoker male with history of polysubstance use disorder was brought to the emergency department from a detoxification program after being found down seizing. He was febrile, hypotensive, tachycardic and hypoxic on presentation. Patient was intubated for airway protection from post-ictal state. Initial lab work was remarkable for rhabdomyolysis, acute kidney injury, mildly elevated aminotransferases, and leukocytosis with bandemia. Computed tomography (CT) of the thorax showed a 7.5 x 7.7 x 8.9 cm cavitating lesion with thick irregular walls in the right lung, 2.5 x 2.8 x 2 cm cavitary lesion with a second smaller cavitating lesion in the left lower lobe; bronchiectasis, dense consolidation, and air bronchograms. Patient was placed on piperacillin/ tazobactam (Zosyn) and vancomycin. Sputum cultures from tracheal aspirate grew pansensitive e. coli. Micafungin was also started when beta-D-glucan was noted to be mildly elevated. Serial acid-fast bacterial (AFB) sputum cultures, and QuantiFERON-TB Gold were negative. Bronchoalveolar lavage (BAL) samples were also negative for malignant cells, and fungal cultures/AFB smears. Transthoracic echocardiogram showed no signs of vegetation. Repeat CT thorax on day 11 showed new 10 mm left upper lobe nodule with persistent cavitary lesions which prompted addition of inhaled tobramycin, switch Zosyn to cefepime, and change of micafungin to amphotericin B until histoplasma antibodies and Aspergillus galactomannan testing returned negative. Patient clinically improved and was extubated after 22 days on the ventilator. DISCUSSION: In our case, e. coli was identified in the first set of sputum cultures, with negative microbiological workup for the rest of the patient's hospitalisation. The mechanism of e. coli NP is unclear but may be a result of microaspiration of upper airway secretions colonised with e. coli with underlying diseases like diabetes mellitus and alcoholism [3]. Incidence of NP is rare and management can be challenging due to lack of guidelines. Intravenous antibiotic therapy remains the mainstay treatment of NP and pulmonary resection is reserved for patients who do not respond to antibiotic therapy or develop parenchymal complications of pulmonary gangrene [1]. CONCLUSIONS: NP can have a prolonged clinical course with increased morbidity. E. coli is an emerging causative organism for NP and should be considered in differential diagnosis. Though work-up is warranted to ensure isolation and treatment of the appropriate organisms. Reference #1: Krutikov, M et al. "Necrotizing pneumonia (aetiology, clinical features and management).” Current Opinion in Pulmonary Medicine vol 25 (3) 225-32. May 2019, doi: 10.1097/MCP.0000000000000571 Reference #2: Harsha, N S et al. "A rare cause of cavitatory pneumonia.” Respiratory medicine case reports vol. 19 125-7. 27 Aug. 2016, doi:10.1016/j.rmcr.2016.08.011 Reference #3: Puri, M M et al. "Pneumatocele formation in adult Escherichia coli pneumonia.” Annals of thoracic medicine vol. 6,2 (2011): 101-2. doi:10.4103/1817-1737.78434 DISCLOSURES: no disclosure on file for Shoaib Ahmad; No relevant relationships by Nasir Alhamdan No relevant relationships by Rishabh Bansal No relevant relationships by Abira Usman No relevant relationships by Vishruth Vyata No relevant relationships by Ashley White