Bloodstream infections in adult patients with malignancy, epidemiology, microbiology, and risk factors associated with mortality and multi-drug resistance
Bloodstream infections in adult patients with malignancy, epidemiology, microbiology, and risk factors associated with mortality and multi-drug resistance
Ali Amanati,1Zahra Shahhosein,2,*
1. Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran 2. Division of Laboratory Hematology and Blood Banking, Department of Medical Laboratory Science, School of Paramedical Science, Shiraz University of medical Science, Shiraz, Iran.
Introduction: The main goal of this study is to find out about the epidemiology, microbiology, and risk factors related to mortality and multi-drug resistance Bacterial Bloodstream Infections (BSIs) in adult patients with cancer in Shiraz, Iran. A four-year trend of antimicrobial resistance pattern of BSIs is reported too.
Methods: A retrospective study was done on all adult patients with confirmed BSI who were referred to the center of oncology from July 2015 to August 2019
Results: During this four-year study, 2393 blood cultures were tested which 414 of them were positive and included in our study. Our patients were about 47.57 ± 17.46 years old, on average. The most detected bacteria were Gram-negative (GN) which were 63.3%(262), just 36.7%(152) of our positive cases were diagnosed with gram-positive bacteria. the most common gram-negative organism was Escherichia coli (123/262, 47%), followed by Pseudomonas spp. (82/262, 31%) and Klebsiella pneumoniae (38/262, 14.5%). The most frequently isolated pathogen among gram-positive bacteria (83/152, 54.6%) was Coagulase-negative staphylococci (CoNS). The most common Extended[1]Spectrum Beta-Lactamase (ESBL) producers detected in our study were Acinetobacter spp., Pseudomonas spp., E. coli, and K. pneumoniae (100, 96.2, 66.7%, and 60.7, respectively). ). The most common carbapenem-resistant (CR) organisms isolated in this study were Acinetobacter spp., Pseudomonas spp., Enterobacter spp., E. coli, and K. pneumoniae (77.8, 70.7, 33.3, 24.4, and 13.2%, respectively). 39.3% of Enterobacterales and non-fermenter gram-negative BSIs were carbapenem-resistant. During these four years, from 2015 to 2018, the prevalence of multi-drug resistance (MDR) gram-negative BSI raised annually, not any changes was seen in the rate of mortality of gram-negative BSI which is about 20% (p-value = 0.55); although, patients with resistant gram-positive BSI had significantly higher mortality rate (35.4%, p-value = 0.001).
Conclusion: One of the most emergent problems, especially in oncology centers, is the prevalence of MDR gram-negative BSI. CR and ESBL-producing Enterobacterales and Pseudomonas spp are the most isolated pathogens. Just a few choices are available to treat MDRGN BSI effectively, especially in high-risk cancer patients, so the need for newer treatment is of great concern.