Antimicrobial susceptibility of Escherichia coli from patientsʼ blood cultures

Bakterija Escherichia coli dio je crijevnog mikrobioma ljudi i toplokrvnih životinja, ali je i oportunistički patogen koji uzrokuje crijevne i vancrijevne infekcije. Cilj ovog rada je ispitati osjetljivost bakterije E. coli na antibiotike iz hemokultura pacijenata iz KBC Split u 2021. g. i utvrditi učestalost ESBL – producirajućih (engl. extended – spectrum – beta – lactamases) i CRE – sojeva (engl. carbapenem – resistant – Enterobacteriaceae). Izolati su redom bili najosjetljiviji na fosfomicin, karbapeneme, aminoglikozide, antibiotike koje sadrže inhibitore beta – laktamaze, zatim na cefalosporine, florokinolone, sulfonamide, a najrezistentniji bili su na peniciline. Utvrđeno je da je 12,2% izolata pripadalo ESBL – producirajućim sojevima, dok nijedan izolat nije pripadao CRE – sojevima. ESBL – producirajući sojevi pokazali su višu stopu rezistencije na peniciline, cefalosporine, fluorokinolone, sulfonamide i nešto višu stopu rezistencije na aminoglikozide i antibiotike koji sadrže inhibitore beta – laktamaza, u odnosu na izolate koji ne proizvode ESBL. ESBL – producirajući sojevi bili su osjetljiviji na antibiotike koji sadrže inhibitore beta – laktamaza, u odnosu na peniciline i cefalosporine koji ne sadrže inhibitore beta – laktamaza.Bacterium Escherichia coli is a part of a healthy gut microbiome of humans and warm-blooded animals. It is also an opportunistic pathogen, which causes intestinal and extra-intestinal infections. The aim of this thesis was to test antimicrobial susceptibility of E. coli from blood cultures of patients tested in KBC Split in 2021 and to determine the frequency of ESBL – producing (extended – spectrum – beta – lactamases) and CRE – strains (carbapenem – resistant – Enterobacteriaceae). Isolates were the most susceptible to fosfomycin, carbapenems, aminoglycosides, antibiotics with beta – lactamase inhibitors, cephalosporins, fluoroquinolones, sulphonamides and finally penicilins. It was determined that 12,2 % of isolates were ESBL – producing and none of them was CRE. ESBL – producing strains showed a higher percent of resistance towards penicilins, cephalosporins, fluoroquinolons, sulponamides, slightly higher percent of resistance towards aminoglycosides and antibiotics with beta – lactamase inhibitors, in comparison with non-ESBL producing strains. ESBL – producing strains were more susceptible to antibiotics containing beta – lactamase inhibitors, compared to penicilins and cephalosporins which do not contain beta – lactamase inhibitors