Distribution of Microorganisms and Antibiotic Resistance Rates Isolated From Blood Cultures: 5-Year Evaluation in a University Hospital in Northern Cyprus

Abstract

Objective: Bloodstream infections (BSI) are considered to be the most important cause of morbidity and mortality. The main purpose of this study is to examine the distribution of microorganisms in blood cultures and the rates of antimicrobial resistance. Methods: Microorganisms isolated from 7.866 blood cultures which were sent to our laboratory between January 2016-December 2020 were retrospectively evaluated. Blood culture bottles were incubated in BACTEC 9120 system. Blood samples were taken from the bottles with a sterile syringe and cultured on Eosin-Methylene Blue (EMB) and 5% sheep blood agars if there was a positive signal. The cultivated cultures were left to incubate at 35°C for 24-48 hours. VITEK 2 compact automated system was used for identification and antibiotic susceptibility tests (AST). Results: Growth was detected in 691 (8.8%) of blood cultures. There were 56.7% gram-negative, 42.7% gram-positive bacteria and 0.6% Candida species. The most common bacteria isolated are; coagulase negative staphylococci (CNS) (21.1%), Escherichia coli (15.2%), Klebsiella pneumoniae (11.9%) and Staphylococcus aureus (11.4%). The rate of ESBL-Escherichia coli increased in 2020, but this was not statistically significant. ESBL-Klebsiella pneumoniae species showed a significant increase over the years and reached the highest level (69.6%) in 2019. MDR (multi drug resistance) rate for Pseudomonas aeruginosa was determined as 13%. MDR rate for Acinetobacter baumannii was determined as 97%. The rate of methicillin resistant Staphylococcus aureus among patients is 30.4%. Conclusions: It is critical to determine microorganisms and their antibiotic susceptibilities as soon as possible in BSI. Active surveillance systems help manage the BSI.