OXA-48-like carbapenemases: the phantom menace

• Published in: Journal of antimicrobial chemotherapy Vol. 67; no. 7; pp. 1597 - 1606
• Main Authors: Poirel, Laurent, Potron, Anaïs, Nordmann, Patrice
• Format: Journal Article
• Language: English
• Published: England Oxford Publishing Limited (England) 01.07.2012
• Subjects: Amino acid substitution; Amino acids; Anti-Bacterial Agents - metabolism; Bacteria; Bacterial Proteins - genetics; Bacterial Proteins - secretion; beta -Lactamase; beta-Lactam Resistance; beta-Lactamases - genetics; beta-Lactamases - secretion; carbapenemase; Carbapenems; Carbapenems - metabolism; Cephalosporins; Enterobacteriaceae - enzymology; Enterobacteriaceae - genetics; Enterobacteriaceae Infections - epidemiology; Enterobacteriaceae Infections - microbiology; Enzymes; Gene expression; Gene Transfer, Horizontal; Global Health; Hospitals; Humans; Hydrolysis; Insertion sequences; Penicillin; Penicillins - metabolism; Permeability; Plasmids; Prevalence
• ISSN: 0305-7453; 1460-2091; 1460-2091
• DOI: 10.1093/jac/dks121

OXA-48-type carbapenem-hydrolysing class D β-lactamases are increasingly reported in enterobacterial species. To date, six OXA-48-like variants have been identified, with OXA-48 being the most widespread. They differ by a few amino acid substitutions or deletions (one to five amino acids). The enzymes hydrolyse penicillins at a high level and carbapenems at a low level, sparing broad-spectrum cephalosporins, and are not susceptible to β-lactamase inhibitors. When combining permeability defects, OXA-48-like producers may exhibit a high level of resistance to carbapenems. OXA-163 is an exception, hydrolysing broad-spectrum cephalosporins but carbapenems at a very low level, and being susceptible to β-lactamase inhibitors. The bla(OXA-48)-type genes are always plasmid-borne and have been identified in association with insertion sequences involved in their acquisition and expression. The current spread of the bla(OXA-48) gene is mostly linked to the dissemination of a single IncL/M-type self-transferable plasmid of 62 kb that does not carry any additional resistance gene. OXA-48-type carbapenemases have been identified mainly from North African countries, the Middle East, Turkey and India, those areas constituting the most important reservoirs; however, occurrence of OXA-48 producers in European countries is now well documented, with some reported hospital outbreaks. Since many OXA-48-like producers do not exhibit resistance to broad-spectrum cephalosporins, or only decreased susceptibility to carbapenems, their recognition and detection can be challenging. Adequate screening and detection methods are therefore required to prevent and control their dissemination.