Background Raoultella terrigena (formerly Klebsiella terrigena) is an environmental gram-negative rod, occasionally causing infections in humans, especially in elderly, immunosuppressed patients. Moreover, this organism tends to be multi-drug resistant, limiting treatment options. Evidence on clinical presentation and outcomes of this infection is limited; we conducted a cross-sectional study to get a better insight into these infections. Methods We conducted a cross-sectional study on all adult patients with clinical specimen positive for Raoultella terrigena at a 700-bedded tertiary care hospital in Karachi, Pakistan, between January 2013 to December 2018. Results A total of 58 patients with R. terrigena were identified. The median age was 61.5 years, and the male to female ratio was (60.9% vs. 39.1%). The most common site of infection was respiratory tract 28.3%, followed by urinary tract infections 26%, and central line-associated infections 15.2%. In 12 patients 22.6%, R. terrigena was a colonizer. Amongst infected cases, 23.6% were in shock, and of which 18.1% required vasopressors. 29.2% had respiratory failure requiring non-invasive ventilation in 13.9%, and mechanical ventilation in 15.3%. The previous history of multidrug-resistant organisms was present in 67.4% cases and the history of prior antibiotics use within the last six months was present in 78.3%. 91.3% of isolates were resistant to piperacillin-tazobactam and meropenem, 65.2% were resistant to colistimethate. However, tigecycline susceptibility maintained in 30.4% checked in n=31, 67.4% and fosfomycin sensitivity in 15.2% cases, checked in n=29, 63% cases. Eight patients lost to follow up. Majority of patients were treated with combination therapy n=31, 81.6% and meropenem plus colistemethate was the most commonly used combination n=11, 44%. The overall mortality rate was 44.7%. Among all recorded co-morbid conditions, chronic kidney disease was strongly associated with mortality (p= .029), as also the use of vasopressors (p= .005).Persons who had high (greater or equal to three) Charlson comorbidity index had high mortality (p=0.002). Conclusion R.terrigena is a highly drug-resistant organism with high mortality rate, and causes hospital-acquired respiratory tract infections in majority of patients. Disclosures All Authors: No reported disclosures

Objectives:Raoultella terrigena (formerly Klebsiella terrigena) is an environmental gram-negative rod. It may cause infections in humans, especially in the elderly and immunosuppressed patients. Moreover, this organism tends to be multi-drug resistant, limiting treatment options. Evidence on clinical presentation and outcomes of this infection is limited. We conducted this study to see its various clinical features, available treatment options, and associated clinical impacts of the R.terrigena infections. Methodology:We conducted a cross-sectional study on all adult patients with clinical specimens positive for Raoultella terrigena at a 700-bedded tertiary care hospital in Karachi, Pakistan, between January 2013 to December 2018. Results:There were 58 patients with R.terrigena in different cultures specimens identified. Amongst them n=12 (22.6%) were colonizers. The median age was 61.5 years (IQR=28), and most were male (60.9%). The most common infection site was the respiratory tract in 28.3%, followed by urinary tract infections, 26%, and central line-associated infections at 26.1%. Amongst infected cases, 37% were in septic shock, and of which 76.5% required vasopressors. 45.7% had respiratory failure requiring non-invasive ventilation in 47.6%, and mechanical ventilation in 52.4%. The previous history of multidrug-resistant organisms was present in 67.4% of patients and the history of prior antibiotics use within the last six months was present in 78.3%. 91.3% of isolates were resistant to piperacillin-tazobactam and meropenem, 65.2% were resistant to colistemethate. Eight patients lost to follow up. The majority of patients treated with combination therapy (n=31, 81.6%) and meropenem plus colistemethate was the most commonly used combination (n=11, 44%). The overall mortality rate was 44.7%. Conclusion: R.terrigena is a highly drug-resistant organism with a high mortality rate and causes hospital-acquired respiratory tract infections in most patients.