Fighting Resistance in Bloodstream Infections

Sepsis: a term dreaded by health care professionals everywhere. At best, it heralds urgent care for a severely ill patient, but can result in death in the worst-case scenario. The high mortality rate that accompanies bloodstream infections is exacerbated by an increase in bacterial resistance to carbapenem antibiotics. Bacteria that produce the resistance enzyme carbapenemase can be detected by laboratory tests, but these can take up to 72 hours to complete. A new immunochromatographic test (1) has now been developed that drastically reduces the amount of time needed to identify carbapenemase-producing Enterobacteriaceae (CPE). Axel Hamprecht of the German Centre for Infection Research says that the new test, which he helped create, will optimize the use of antibiotic treatments.

“The incidence of bloodstream infections with CPE is rising and currently there is no method available for its rapid detection. We have developed an immunochromatographic lateral flow assay, whereby carbapenemases are detected by monoclonal antibodies specific for carbapenemase epitopes,” explains Hamprecht. “Once we discover that a bloodstream infection is caused by CPE, we can begin treatment with drugs such as colistin or fosfomycin, in combination with other antibiotics. Our assay can then detect the type of carbapenemase present so that the most effective drug can be used.”

Hamprecht continues; “Every minute counts in patients with sepsis, and delaying the administration of effective therapy leads to increased mortality – an increase of 7 percent per hour in severe cases. This method can detect CPE in just 20 to 45 minutes, which is much faster than conventional techniques.” The research team behind the method believe that the test is well-suited for clinical laboratories, and are further developing the assays to detect rare types of CPE.

There is a large degree of variation in CPE prevalence around the globe, and in countries such as India, Greece and Italy, over half of Klebsiella pneumoniae hospital isolates are carbapenemase producers. Even in the US, they have been found in every state other than Maine and Idaho. This is no minor threat; carbapenems are often used as a last line of defense against Enterobacteriaceae, so every advantage counts.