[Current data and trends about the resistance of Gram-negative pathogens to beta-lactams].

In recent years the resistance of Gram-negative pathogens to beta-lactam antibiotics, such as cephalosporins and carbapenems has increased. The resistant strains produce different beta-lactam hydrolysing enzymes (beta-lactamases). In particular extended spectrum beta-lactamases (ESBL) are prevalent in Escherichia coli and Klebsiella pneumoniae. The ESBL genes are located on different plasmids facilitating the transfer of resistance within a species and between different Gram-negative species. Within the scope of various studies the Robert Koch Institute in Wernigerode investigated ESBL-producing human Enterobacteriaceae using molecular methods. The results showed that distinct ESBL types, such as the CTX-M enzymes are dominant in Germany whereby CTX-M-15 and CTX-M-1 are the most prevalent variants in E. coli and K. pneumoniae. The aim of ongoing investigations within the RESET network project is to investigate the dissemination pathways of ESBL-producing bacteria in different settings (e.g. in humans, animals and food).