RESUMO
Objective To investigate the risk factors for childhood acute leukemia complicated with streptococcus mitis bacteriaemia and to explore a better therapeutic regimen of antibiotics.Methods Seventy-eight cases of childhood acute leukemia complicated with bacteriaemia hospitalized in Zhujiang Hospital of Southern Medical University from January 2012 to December 2016 were collected,among them there were 8 cases (10.26％) caused by streptococcus mitis.The susceptible factors,clinical manifestations,drug susceptibility,treatments and outcomes of 8 cases of streptococcus mitis bacteriaemia were summarized and analyzed.Results All of 8 cases were attacked during the agranulocytosis phase lasting for more than 1 week after chemotherapy for acute leukemia.Four cases of them had been exposed to the third-generation cephalosporins for more than 7 days,and 5 cases exposed to proton pump inhibitor (PPI) for more than 10 days.The incidence of remittent fever,shiver,stomatitis and pneumonia was 100.0％ (8/8 cases),62.5％ (5/8 cases),62.5％ (5/8 cases) and 62.5％ (5/8 cases),respectively.And severe pneumonia occurred at a rate of 37.5％ (3/8 cases).The sensitivity to Linezolid,Vancomycin,Penicillin and Cefotaxime was 100.0％,100.0％,37.5％ and 25.0％,respectively.Five of the 7 cases treated with Meropenem had a fever 3 days later and then they took Linezolid as a replacement according to the drug sensitivity.One case was treated with Cefoperazone-Sulbactam.The duration time of fever,positive blood culture,agranulocytosis and course of antibiotics therapy was 1-19 d(10.4 d on average),4-22 d(13.4 d on average),10-30 d (21.6 d on average),9-26 d (18.3 d on average),respectively.Among 3 patients with severe pneumonia,1 patient received the respirator assisted ventilation for 1 week.Conclusions Streptococcus mitis is one of the major causes of severe infection among children with acute leukemia.Agranulocytosis after chemotherapy,stomatitis,exposure to PPI and antibiotics may be the risk factors for streptococcus mitis infection.Fever,stomatitis,respiratory and digestive symptoms are the common clinical manifestations.Streptococcus mitis is resistant to Penicillin and Cefotaxime,but sensitive to Linezolid,which can shorten the course of infection and improve the outcomes.Thus,Linezolid may serve as an optional therapy for streptococcemia mitis bacteriaemia.
