Plasmid mediated antibiotic resistance

Enterobacteriaceae is a family of bacteria including Escherichia coli and Klebsiella pneumoniae that are common colonizers of the gastrointestinal tract. Extended spectrum βlactamases (ESBL) are bacterial enzymes that degrade β-lactam antibiotics and thus make the bacteria resistant to β-lactam antibiotics. ESBL-producing Enterobacteriaceae (EPE) is an increasing problem constituting a burden on health care systems conferring excess morbidity, prolonged hospital stay and mortality. There are many hundreds of different ESBL-genes described. The most common are the blaCTX-M group. ESBL-genes are often situated on plasmids. This enables a fast dissemination since they can be spread both vertically and horizontally. Horizontal dissemination also enables them to spread between bacteria of different species. Outbreaks of resistant bacteria, such as EPE, must be rapidly detected and contained. Today the main focus during an outbreak is to conduct epidemiological typing of the bacterial strain. However, a horizontal outbreak of resistance genes in the bacterial population can also occur and go undetected if only the strain is subjected to epidemiological typing. There is a need for better understanding of plasmid dissemination and their role in transferring antibiotic