NCTC Control Strains for UK Standards for Microbiological Investigations (SMIs)
The UK Health Security Agency (UKHSA) in conjunction with its partner organisations develops SMIs to help to assure equivalence of investigation strategies in different laboratories; all the SMI Test Procedures (TPs) for bacteriology stipulate the use of control strains from the National Collection of Type Cultures (NCTC). Controls are necessary to help demonstrate that laboratory procedures are being operated and interpreted correctly.
For further information or to download any of the Standards for Microbiological Investigations go to the UK Standards for Microbiology Investigations webpage
Culture Collections now provide a cost effective means for clinical microbiology laboratories to update their stock cultures of the 17 NCTC strains needed for the SMI TPs in a single order. The SMI TP NCTC set (17 strains) includes all the 17 controls listed below:
Species name |
NCTC number |
SMI TP control strain information |
|
Acinetobacter Iwoffii |
negative control for TP21 (motility) and TP27 (fermentation of glucose) |
|
| Clostridium difficile | 11204 | negative control for TP22 (Nagler) |
| Clostridium perfringens | 8359 | positive control for TP22 (Nagler) |
| Enterococcus faecalis | 12697 | positive control for TP2 (aesculin hydrolysis) |
| Escherichia coli | 10418 | positive control for TP19 (indole), TP24 (ONPG (ß-galactosidase)) for Enterobacteriaceae, TP27 (fermentation of glucose) and TP30 (potassium hydroxide)
negative control for TP26 (oxidase) and TP36 (urease) |
| Haemophilus influenzae | 11931 |
positive control for TP38 (x and v factors) negative control for TP29 (porphyrin synthesis (ala)) |
| Haemophilus parainfluenzae | 10665 |
positive control for TP29 (porphyrin synthesis (ala)) negative control for TP38 (x and v factors) |
|
Micrococcus luteus |
2665 |
positive control for TP27 (oxidation of glucose) |
| Neisseria gonorrhoeae | 8375 | negative control for TP24 (ONPG (ß-galactosidase)) for Neisseria spp. |
| Neisseria lactamica | 10617 | positive control for TP24 (ONPG (ß-galactosidase)) for Neisseria spp. |
| Proteus mirabilis | 10975 | positive control for TP21 (motility) and TP36 (urease)
negative control for TP19 (indole) and TP 24 (ONPG) (ß-galactosidase)) for Enterobacteriaceae |
| Pseudomonas aeruginosa | 10662 | positive control for TP26 (oxidase) and TP27 (oxidation of glucose) |
| Staphylococcus aureus | 6571 | positive control for TP8 (catalase), TP10 (coagulase), TP12 (deoxyribonuclease), TP27 (fermentation of glucose) and TP34 (thermonuclease)
negative control for TP30 (potassium hydroxide) |
| Staphylococcus haemolyticus | 11042 | negative control for TP10 (coagulase), TP12 (deoxyribonuclease) and TP34 (thermonuclease) |
| Streptococcus agalactiae | 8181 | negative control for TP2 (aesculin hydrolysis) |
| Streptococcus mitis | 10712 | negative control for TP5 (bile solubility), TP8 (catalase) and TP25 (optochin) |
| Streptococcus pneumoniae | 12977 | positive control for TP5 (bile solubility) and TP25 (optochin) |