A-290 Prevalence and Antimicrobial Resistance Pattern of Microorganisms Recovered From Bloodstream Infections From Public Hospitals of São Paulo City, Brazil

Abstract

Abstract Background Nosocomial Bloodstream Infections (nBSI) are an important cause of morbidity and mortality. Brazilian studies concerning bloodstream infections are important tools that can bring specific issues related to antimicrobial resistance. The objective of this study was to describe the frequency and antimicrobial susceptibility profile of bacterial isolates from BSI in patients admitted to public hospitals in 2022 and 2023. Methods This study was a retrospective analysis from 12 hospitals (January 2022 to December 2023) based on BSI isolates laboratory data detected by the clinical microbiology department of a medical diagnostic laboratory. The identification and susceptibility tests were performed using MALDI-TOF mass spectrometry (Vitek MS) and Vitek®2 systems, according to the manufacture’s recommendations. Coagulase Negative Staphylococci (CoNS) BSI was only considered in the presence of at least two sets of positive blood cultures with the same organism. Results During the period (January 2022 to December 2023) a total of 19,588 microorganisms isolated from BSI were obtained from 12 hospitals. The frequency of organism group was Gram-positive (10,707; 54.7%), Gram-negative (7,874; 40.2%), yeasts (961; 4.9%) and filamentous (46; 0.2%). The order of prevalence (top ten) organisms was CoNS (5,149; 26.3%); Staphylococcus aureus (2,769; 14.1%); Klebsiella spp. (2,355; 12.0%); Escherichia coli (1,301; 6.6%); Acinetobacter spp. (1,293; 6.6%); Streptococcus spp. (1,125; 5.7%); Enterococcus spp. (1,112; 5.7%); Candida spp. (937; 4.8%); Pseudomonas spp. (749; 3.8%) and Proteus spp. (553; 2.8%). Extended spectrum beta-lactamase rates for E. coli and Klebsiella pneumoniae were 31.6% (268/848) and 74.9% (1027/1371), respectively. The resistance to carbapenems was detected mainly in 74.1% (661/892) of Acinetobacter spp. isolates, 60.7% (832/1371) of Klebsiella pneumoniae; 24.5% (114/465) of P. aeruginosa; 9.7% (34/349) of Proteus spp. and 1.4% (12/828) of Escherichia coli. Antimicrobial resistance was observed mainly in 87.2% of CoNS (2831/3247) and 44.5% of S. aureus (743/1669) to methicillin; 22.9% (146/637) of Enterococccus spp. to vancomycin. Conclusions The frequency of Klebsiella spp. isolates from nBSI has progressively increased and effective infection control measures should be taken to prevent them from spreading. The rates of antimicrobials resistance reported for Klebsiella pneumoniae, Acinetobacter spp., CoNS, S. aureus and Enterococcus spp. reinforce the high resistance rates to antimicrobials in São Paulo city.