in the United States. A carbapenem-resistant
strain known as multilocus sequence type 258 (ST258) is one of the antibiotic-resistant organisms labeled an urgent threat by the Centers for Disease Control and Prevention. ST258 is particularly concerning because it is resistant to most antibiotics. It is a significant cause of mortality among people with bloodstream infections.
‘Antibody treatment alone or in combination with antibiotics could greatly improve care for people with multidrug-resistant K. pneumonia infections.’
The scientists first determined that the bacterial capsule prevents immune system neutrophils from ingesting and killing ST258. They then extracted capsule from the two most abundant capsule types of ST258 and used them to generate antibodies in rabbits. In cell culture experiments they found that one of the antibodies enhanced the ability of neutrophils to ingest and kill bacteria. These results are a "proof of concept" for a potential immunotherapy approach for treatment of multidrug-resistant K. pneumonia
infections, the authors write.
Next up, the scientists will test the therapeutic concept in mice. They also will compare immunization with purified capsule polysaccharide as a preventive approach (active immunization) versus using capsule-specific antibodies as a therapy (passive immunization). Ultimately, they hope either antibody treatment alone or in combination with antibiotics could greatly improve care for people with multidrug-resistant K. pneumonia