Sub-MICs of sanfetrinem promote the interaction of human polymorphonuclear granulocytes with a multiply resistant strain of Klebsiella pneumoniae.

The effect of sanfetrinem, a member of a new class of antibiotics, upon the in-vitro interaction between human polymorphonuclear granulocytes (PMNs) and a multiply resistant strain of Klebsiella pneumoniae was investigated. Sub-MICs of sanfetrinem significantly enhanced PMN phagocytosis and greatly reduced the survival of intracellular bacteria compared with antibiotic-free systems. The distinction between any effect of sanfetrinem on the klebsiellae and the phagocytes was made by exposing each of them to the drug before they were incubated together. The results indicate that sanfetrinem may have a direct positive action either on K. pneumoniae or on human granulocytes.