Patients with cancer have a higher risk of severe bacterial infections. This study aims to determine the frequency, susceptibility profiles, and resistance genes of bacterial species involved in bacteremia, as well as risk factors associated with mortality in cancer patients in Colombia. In this prospective multicenter cohort study of adult patients with cancer and bacteremia, susceptibility testing was performed and selected resistance genes were identified. A multivariate regression analysis was carried out for the identification of risk factors for mortality. In 195 patients, 206 microorganisms were isolated. Gram-negative bacteria were more frequently found, in 142 cases (68.9%): 67 Escherichia coli (32.5%), 36 Klebsiella pneumoniae (17.4%), and 21 Pseudomonas aeruginosa (10.1%), and 18 other Gram-negative isolates (8.7%). Staphylococcus aureus represented 12.4% (n = 25). Among the isolates, resistance to at least one antibiotic was identified in 63% of them. Genes coding for extended-spectrum beta-lactamases and carbapenemases, blaCTX-M and blaKPC, respectively, were commonly found. Mortality rate was 25.6% and it was lower in those with adequate empirical antibiotic treatment (22.0% vs. 45.2%, OR: 0.26, 95% CI: 0.1–0.63, in the multivariate model). In Colombia, in patients with cancer and bacteremia, bacteria have a high resistance profile to beta-lactams, with a high incidence of extended-spectrum beta-lactamases and carbapenemases. Adequate empirical treatment diminishes mortality, and empirical selection of treatment in this environment of high resistance is of key importance.

Background Infections are common complications in patients with cancer. Data on antimicrobial resistance is important to guide empirical antimicrobial therapy. However, resistance rates varies among different regions and countries and, in general, is higher in Latin America. There are limited data from these patients in this region. The aim of this work is to determine the frequency and antibiotic susceptibility profiles, as well as to identify the most frequent genes related to resistance, among microorganisms implicated in bacteremia in patients diagnosed with cancer Methods A cross-sectional multicenter study conducted in six hospitals in Colombia. An active laboratory search was carried out for adult patients with cancer and bacteremia. Data was obtained from the electronic medical records, and according to the resistance of the microorganisms, molecular tests were performed in a standardized way to identify genes related to methicillin-resistance, extended spectrum beta lactamases and carbapenemases. In addition, an exploratory multivariate analysis was performed using a logistic regression method to predict mortality Results 195 patients from 6 hospitals were included in the study. The clinical variables of the patients are described in Table 1. Gram-negative bacteria were more common and their resistance rates were high. The genes found in the different resistant bacterial isolates are described in Table 2; The main resistance genes identified were blaCTX-M and blaKPC, generating ESLB-type beta-lactamases and carbapenemases, respectively. 30 day-mortality was 26%, which is similar to other studies. Multivariate analysis showed that adequate antibiotic treatment (OR: 0.26 (95%CI 0.1-0.63)) and higher number of platelets (per 10,000, OR: 0.97 (95%CI 0.94-0.99)) were associated with survival. Mortality was associated with patients in palliative care (OR 3.51 (95%CI 1.05-12.04)). Conclusion Gram-negative bacilli are frequently found in patients with cancer and bacteremia. A high level of resistance was identified. The frequency of the genes identified varies from what has been described in other regions of the world. Appropriate and prompt treatment in these patient would improve the outcomes. Disclosures Jorge A. Cortés, MD, pfizer: Grant/Research Support Carlos Saavedra-Trujillo, MD, pfizer and merck: Grant/Research Support.