Microbial isolates and resistance profiles in cerebrospinal fluid cultures: a five-year experience at a tertiary center

Central nervous system infections are a significant global health concern that results in morbidity and mortality. In case of these infections, empirical antibiotic treatment should be initiated according to the microbiological findings of the cerebrospinal fluid (CSF), and the treatment should be rearranged according to the antibiogram results.The study aimed to determine the distribution of meningitis agents and antimicrobial resistance patterns in our hospital. A total of 17,594 CSF culture samples collected from January 2020 to December 2024 were analyzed retrospectively. The study assessed demographic data, causative microorganisms, and antimicrobial resistance rates. Positive results were found in 7.3% of CSF culture samples, with 69.1% being gram-positive bacteria and 30.9% gram-negative bacteria. The highest positivity rate was detected in the palliative inpatient clinic (14.8%) despite most cultures being from the neonatal intensive care unit (23.5%). The most common microorganisms were coagulase-negative staphylococci(CoNS) (47.9%) and Klebsiella pneumoniae (K.pneumoniae) (9.1%). Methicillin resistance was present in 89.7% of CoNS, and the rate of extended-spectrum β-lactamase-producing strains in K.pneumoniae was 32.4%. Analysis of five-year data revealed the types of microorganisms and their antimicrobial resistance in positive CSF cultures. These findings will guide clinicians in promptly choosing the most effective empirical treatment.