Whole genome sequencing of antibiotic resistant genes in isolates from surfaces in a Science Laboratory

INTRODUCTION: Isolates obtained from laboratory surfaces were identified and characterized.
METHODS: Ten consecutive isolates were obtained from 30 sample surfaces of a University science laboratory in Edo state Nigeria in May 2021. Swabs of surfaces from the Laboratory were aseptically obtained. The sample swabs were streaked on MacConkey, eosin methylene blue, mannitol salt and Nutrient agar plates respectively and incubated appropriately. Distinct colonies were randomly obtained from culture plates and characterized phenotypically. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry was used to analyze four isolates (40%) obtained by selection criteria. Susceptibility testing using antibiotics was performed for the identified isolates by Kirby-Bauer method for 15 antibiotics. Isolate characterization and identification of resistance determinants were determined using Whole genome sequencing (WGS).
RESULTS: Microorganisms identified include Leclercia adecarboxylata, Enterobacter hormaecehi, Atlantibacter hermanii and Stenotrophomonas maltophilia. Three identified isolates were resistant to antibiotics and were investigated by whole genome sequencing (WGS). Resistance genes were found in all (100%) of the resistant laboratory isolates. The resistance determinants included β-lactamase genes, aminoglycoside modifying enzymes, qnr genes, sulphonamide, tetracycline and trimethoprim resistance genes, respectively. Two isolates were carrying ESBL genes and blaCTX-M-15 was detected.
DISCUSSION AND CONCLUSION: Our study shows the dissemination of antibiotic resistance among isolates obtained from surfaces of a University science laboratory. To the best of our knowledge we report the first genomic characterization of resistance to antibiotics in isolates obtained from surfaces of a University science laboratory for Nigeria.