Abstract
Abstract: The spread of multidrug-resistant strains of Klebsiella pneumoniae in hospitals is of concern to clinical microbiologists, health care professionals, and physicians because of the impact infections caused by these bacteria have in causing morbidity and mortality. Clinical isolates of K. pneumoniae have been found to show resistance to third generation cephalosporins as a result of acquiring extended-spectrum b-lactamase-producing genes, such as blaCTX-M. Since little is known about the mechanisms of antibiotic resistance observed in Kasserine hospital, Tunisia, this study was undertaken to investigate the mechanisms by which clinical isolates of K. pneumoniae resist b-lactam antibiotics. Twelve strains of K. pneumoniae were collected from patients admitted to Kasserine hospital; these isolates showed multi resistance phenotypes. Molecular genetics investigations using polymerase chain reaction, S1 digestion, and pulsed-field gel electrophoresis showed that blaCTX-M-15 in association with ISEcp1 is responsible for the resistance of these strains to third generation cephalosporins. It has been determined that blaCTX-M-15 is chromosomally mediated and plasmid mediated, which alarming need for infection control to prevent the outbreak of such a resistance mechanism