Extended-spectrum beta-lactamase in the urinary isolates of Enterobacteriaceae

Abstract

Mnogi sojevi enterobakterija uzročnici su infekcija kod čovjeka, najčešće mokraćnog i spolnog sustava, te su često uzročnici infekcija probavnog trakta, dok u zadnje vrijeme postaju sve značajniji uzročnik infekcija povezanih sa zdravstvenom skrbi. Antibiotici su po definiciji farmakološki agensi koji mogu potpuno uništiti bakterije ili zaustaviti njihov rast ili razmnožavanje bez pričinjavanja značajnije štete organizmu domaćinu. U skupine koje djeluju na staničnu stijenku i membranu spadaju beta-laktamski antibiotici. To su: penicilini, cefalosporini i cefamicini, monobaktami, karbapenemi i inhibitori beta-laktamaza. Pojava rezistencije bakterija na antibiotike kompromitira uspjehe antibiotskih terapija i dostignuća medicine. Beta-laktamaze su bakterijski enzimi koji hidrolizom razgrađuju amidnu vezu u beta-laktamskom prstenu penicilina, cefalosporina i monobaktama, stvarajući kiselinske derivate bez antibakterijske aktivnosti. Beta-laktamaze predstavljaju glavni mehanizam rezistencije bakterijskih patogena na beta-laktamske antibiotike. Beta-laktamaze proširenog spektra su plazmidno kodirani enzimi nastali točkastom mutacijom u blaTEM, blaSHV genu, te od kromosomske AmpC beta-laktamaze bakterijske vrste Klyvera ascorbata horizontalnim prijenosom gena i posljedičnom mutacijom. Ovo istraživanje rađeno je na 121 urinarnom izolatu sakupljenom u Kantonalnoj bolnici u Zenici, Bosna i Hercegovina. Poslani su uzorci na koje se sumnjalo na proizvodnju beta-laktamaza proširenog spektra pa se prevalencija ne poklapa s podacima iz dosadašnjih istraživanja jer se ona odnose na prevalenciju u ukupnoj istraživanoj populaciji. Naši rezultati su puno većih vrijednosti. Ti su uzorci testirani na osjetljivost na razne antibiotike, izrađeni su antibiogrami, te su rađeni testovi konjugacije s plazmidima.Many strains of Enterobacteriaceae are causing infections in humans, mostly of the urinary and reproductive system, and often cause gastrointestinal infections, while lately have become important cause of infections associated with the health care. Antibiotics are defined as pharmacological agents that can completely destroy the bacteria or stop their growth or reproduction without causing significant damage to the host organism. The group of antibiotics that act on the cell wall and membrane is beta-lactam antibiotics. These are: penicillins, cephalosporins and cephamicins, monobactams, carbapenems and beta-lactamase inhibitors. The emergence of bacterial resistance to antibiotics compromises the success of the antibiotic therapy and medical achievements. Beta-lactamases are bacterial enzymes that degrade by hydrolysis of amide bond in the beta-lactam ring of penicillins, cephalosporins and monobactams, producing acidic derivates without antibacterial activity. Beta-lactamases represents a major mechanism of resistance of bacterial pathogens in beta-lactam antibiotics. Extended spectrum beta-lactamases are plasmid encoded enzymes became by dott-mutation in blaTEM or blaSHV gene, or from chromosomal AmpC beta-lactamase Klyvera ascorbata by horizontal gene transfer and mutation. This study was obtained from 121 urinary isolates collected in the Cantonal Hospital in Zenica, Bosnia and Herzegovina. Sent samples were suspected of ESBL production and the prevalence does not coincide with the data from previous studies because these were related to the prevalence in the total population. Our results have much larger values. Samples were tested for sensitivity to various antibiotics, antibiograms were made, and conjugation tests were done with plasmids