Septicaemia caused by viridans streptococci in neutropenic patients with leukaemia

10 neutropenic leukaemic patients had septicaemia caused by viridans streptococci, organisms not commonly recognised as opportunist pathogens. 1 patient died; in the remainder recovery was generally dependent on an adequate circulating granulocyte count (seven patients) rather than specific antimicrobial therapy. Seven of the infections were caused by Streptococcus mitis, and seven of the eight strains tested were resistant to cotrimoxazole, which the patients had received as prophylaxis against infection. It is suggested that oral ulceration caused by cytotoxic chemotherapy provided a portal of entry for cotrimoxazole-resistant viridans streptococci. The increasing incidence of infections with gram-positive organisms as a complication of neutropenia prompts a reconsideration of current empirical antimicrobial therapy.