Evaluation of the HB&L carbapenemase and extended spectrum beta lactamase-AmpC automated screening kits for the rapid detection of resistant Enterobacteriaceae in rectal swabs

Background. In the past two decades, a rapid increase of infections due to multidrug-resistant Enterobacteriaceae was reported worldwide, including in Italy. These bacteria express genes encoding for extended-spectrum β-lactamases (ESBL) or bear a plasmid-mediated AmpC that induce phenotypically a resistance to the last-generation cephalosporins; even more worrying is the rapid increase of Enterobacteriaceae carrying genes conferring resistance to carbapenems (CPE).
Materials and methods. The gut may serve as reservoir for these antibiotic drug-resistant bacteria: as a consequence, the rapid detection of drug resistant Enterobacteriaceae from rectal swabs is an important tool to identify rectal carriage of resistant bacteria. This procedure is the basic tool to successfully implement the infection control measures in the hospital wards. The study evaluated the capability of the HB&L ESBL/AmpC and CARBAPENEMASE screening kit (Alifax, Padua, Italy) to rapidly identify the drug resistant enterobacteriaceae from rectal swabs: the performance was compared with the conventional method.
Results and conclusions. The overall agreement was very good (91% for the detection of ESBL-AmpC, and 96.2% for the identification of CPE); this method is thus an efficient tool to quickly report positive multidrug resistant bacteria in rectal swabs.