Clinical comparison of anaerobic blood-culture media for detecting bacteraemia due to viridans streptococci and oral anaerobes.

Brain heart infusion cysteine broth, with and without Panmede (a papain digest of ox liver) and Fastidious Anaerobe Broth, with and without Liquoid, were compared by inoculating the broths with blood collected from each of 51 patients, 2 min after dental extraction. Bacteraemia caused by viridans streptococci or oral non-sporing anaerobes or both was detected in 39 patients (76%). Detection of bacteraemia caused by viridans streptococci and anaerobes was more rapidly achieved by the addition of Panmede to brain heart infusion broth. Significantly more cases of bacteraemia caused by viridans streptococci were detected by use of the Panmede-containing medium than by use of Fastidious Anaerobe Broth after incubation of the broths for only 1 day. Use of brain heart infusion cysteine broth with and without Panmede, and Fastidious Anaerobe Broth permitted detection of bacteraemia caused by viridans streptococci in 26, 11 and 22 patients respectively during incubation for 2 weeks. Bacteraemia caused by anaerobes was detected by use of these three media in 24, 13 and 23 patients respectively. The addition of Liquoid to Fastidious Anaerobe Broth had no significant effect on the detection of bacteraemia caused by viridans streptococci or anaerobes. The Panmede-containing blood-culture medium should be a useful anaerobic broth in the investigation of patients with suspected endocarditis, because viridans streptococci are also rapidly detected.