Disseminated disease due to Mycobacterium chelonei treated with amikacin and cefoxitin. Absence of killing with either agent and possible role of granulocytes in clinical response.

Disseminated disease due to rapidly growing mycobacteria is manifested by positive blood cultures and multiple skin and subcutaneous abscesses. A patient had T-cell lymphoma and disseminated disease; he also had neutropenia intermittently. Single-agent therapy with amikacin sulfate or cefoxitin sodium was not adequate during periods of neutropenia, and combination therapy was necessary to control the infection. Clinical response correlated with detectable serum inhibitory levels of the antimicrobial agents. Surprisingly, the organism was not killed by either amikacin or cefoxitin, a finding that correlated with the absence of serum bactericidal levels. This case suggests that granulocytes may play a role in the host's response to this organism, and determination of serum inhibitory and possible bactericidal levels may be useful in monitoring therapy.