Monday, 13 July 2015

Screening and detection of bacteria with carbapenem hydrolysing β lactamases



The U.K. government has posted a consultation document. The document asks for feedback in relation to the in relation to the SMI B 60: screening and detection of bacteria with carbapenem hydrolysing β lactamases (carbapenemases).

The term ‘carbapenemase’ is used to mean any β-lactamase that hydrolyses carbapenems ie any or all of doripenem, ertapenem, imipenem and meropenem. These carbapenems are antimicrobial drugs of last resort and are crucial for preventing and treating life-threatening nosocomial infections. Of clinical concern, many carbapenemases confer resistance or reduced susceptibility to all or nearly all members of the β-lactam class, not just to carbapenems.

Carbapenemases are intrinsic (found naturally) in a few clinical bacteria, such as Stenotrophomonas maltophilia, Aeromonas species, and ‘chryseobacteria’, including Elizabethkingia meningoseptica. Acinetobacter baumannii also has the gene for an intrinsic carbapenemase (OXA-51like), but this confers reduced susceptibility or resistance to carbapenems only when its expression is up-regulated by genetic reorganisation.

In addition, non-susceptibility or resistance to specific carbapenems is an intrinsic characteristic of some Gram negative bacteria: most non-fermenters are naturally resistant to ertapenem (but not to other carbapenems); Serratia species and Proteeae have intrinsic poor susceptibility or low-level resistance to imipenem (but not to other carbapenems).

The document can be accessed here.

 Posted by Tim Sandle