Table 1.

Cognitor limit of detection for 20 most prevalent pathogens detected in clinical blood cultures.a

Organism nameLowest detectable density (CFU/mL)
Acinetobacter sp.70
Bacteroides sp.219
Candida albicans250
Candida glabrata257
Candida parapsilosis201
Citrobacter sp.50
Clostridium perfringens900
Enterobacter cloacae132
Enterococcus faecalis227
Escherichia coli75
Haemophilus influenzae140
Klebsiella pneumoniae52
Neisseria lactamicab9050
Proteus mirabilis156
Pseudomonas aeruginosa28
Salmonella sp.35
Serratia marcescens32
Staphylococcus aureus58
Streptococcus mitis107
Streptococcus Group A225
  • a Lowest detectable cell density required for a positive result in the manual Cognitor test. Cell densities were estimated by total viable counts at the time of running the Cognitor test. Organisms represent the most prevalent causes of bacteremia and fungemia in the UK, 2014 (21).

  • b Neisseria lactamica was used in place of Neisseria meningitidis because of health and safety restrictions on the use of N. meningitidis in the research laboratory.