Results of a 10-month Study on the Species Spectrum and Antimicrobial Resistance of Microorganisms in a Tertiary Care Hospital

Abstract

Introduction. Antimicrobial resistance (AMR) remains a global issue requiring a comprehensive approach to address it. One of the methods to mitigate AMR is the microbiological monitoring of antibiotic-resistant strains of microorganisms within the framework of infection control with regular monitoring of resistance patterns. The aim of thе study. To determine the species diversity and antimicrobial resistance of microorganisms isolated in a tertiary care hospital over a 10-month period. Materials and methods. The study was conducted at the Clinical Bacteriology Laboratory of the Regional Center for Laboratory Diagnostics, Communal enterprise ″Yuri Semenyuk Rivne Regional Clinical Hospital″ of Rivne Regional Council (Rivne, Ukraine) over 10 months (July 2023 - April 2024). From 8.300 patients, 12.463 biological samples were collected, from which 16.618 strains of microorganisms were isolated and studied. Pure culture isolation was performed using bacteriological methods with nutrient media. Species identification and antimicrobial susceptibility testing were carried out using a semi-automated bacteriological analyzer ID/AST system D2mini with plates produced by Zhuhai DL Biotech Co. Ltd., in accordance with EUCAST 2023-2024 guidelines. Results. During the 10 months of observation, 16.618 strains of microorganisms were identified and their antimicrobial resistance levels were determined. Of these, 64.4 % were gram-negative bacteria, 32.5 % were gram-positive microorganisms, and 3.0 % were yeast fungi. The most common gram-negative bacteria were Klebsiella pneumoniae (40.8 %), Pseudomonas aeruginosa (18.2 %), and Acinetobacter baumannii (14.4 %). Among the gram-positive bacteria, Staphylococcus aureus (39.5 %), Staphylococcus epidermidis (15.5 %), and Staphylococcus haemolyticus (14.1 %) were predominant. The most common yeast fungi of the Candida genus were Candida albicans (60.5 %), Candida guilliermondii (12.5 %), and Candida tropicalis (8.9 %). High resistance was found to second-generation cephalosporins (81.4 % resistant strains to cefalexin) and fourth-generation cephalosporins (67.2 % resistant to cefepime), as well as aminopenicillins (amoxicillin-clavulanate – 76.1 %, ampicillin – 75.1 %). High sensitivity was noted to antibiotics of the tetracycline group (78.5 % to tetracycline), glycylcyclines (93.5 % to tigecycline), oxazolidinones (93.5 % to tigecycline), and lincosamides (80.8 % to clindamycin). Conclusions. A total of 16.618 strains of microorganisms were identified, with 64.4 % being gram-negative bacteria, 32.5 % gram-positive microorganisms, and 3.0 % yeast fungi. High resistance was found to second- and fourth-generation cephalosporins and aminopenicillins. High sensitivity was detected to antibiotics of the tetracycline, glycylcycline, oxazolidinone, and lincosamide groups.