More rapid identification of bacteraemia by manual rather than radiometric method

Results of blood culture examination using the radiometric (Bactec-460) system for one year showed no overall improvement compared with those of the previous three years when a manual system with early blind subculture was used. The isolates from the manual system were available more often on solid media, 24 hours earlier, than when the radiometric system was used. In a further study of 1100 blood cultures the radiometric medium was tested for growth index as well as being subcultured blindly, irrespective of growth index, on the first day. Thirty six out of 54 (67%) of the blood cultures were positive on subculture but negative for growth index at this time. The overall cost of the radiometric system is also considerably more than that of the manual system.