NCTC Antimicrobial Susceptibility Testing Controls
The Health Protection Agency's National Collection of Type Cultures (NCTC) offers a wide range of strains that can be used to conrol antimicrobial susceptibility testing to:
- monitor test performance
- confirm that the in-use method will detect resistance
NCTC strains are verified by the HPA's Antibiotic Resistance Monitoring and Reference Laboratory (ARMRL) and are used in diagnostic testing laboratories worldwide.
The strains listed are specifically recommended by one or more of the following:
- British Society of Antimicrobial Chemotherapy (BSAC)
- United Kingdom Standards for Microbiology Investigations (formerly National Standard Methods)
- The European Committee on Antimicrobial Susceptibility Testing (EUCAST)
- United States Clinical and Laboratory Standards Institute (CLSI)
BSAC Method for Antimicrobial Susceptibility Testing (Version 10.2 May 2011)
Susceptible control strains or control strains with low level resistance
| Organism | NCTC® Strain Reference | Characteristics |
| Escherichia coli | NCTC 12241 | Susceptible (β-lactamase negative) |
| NCTC 10418 | Susceptible | |
| Staphylococcus aureus | NCTC 12981 | Susceptible (β-lactamase negative) |
| NCTC 6571 | Susceptible | |
| Pseudomonas aeruginosa | NCTC 12903 | Susceptible (contains inducible AmpC β-lactamase) |
| NCTC 10662 | Susceptible | |
| Enterococcus faecalis | NCTC 12697 | Susceptible |
| Haemophilus influenzae | NCTC 11931 | Susceptible |
| Streptococcus pneumoniae | NCTC 12977 | Low level resistant to penicillin (altered penicillin binding protein) |
| Neisseria gonorrhoeae | NCTC 12700 | Low level chromosome mediated resistant to penicillin |
| Pasteurella multocida | NCTC 8489 | Susceptible |
| Bacteroides fragilis | NCTC 9343 | Susceptible |
| Clostridium perfringens | NCTC 8359 | Susceptible |
BSAC Method for Antimicrobial Susceptibility Testing (Version 10.2 May 2011)
Control strains with a resistance mechanism
| Organism | NCTC® Strain Reference | Characteristics |
| Escherichia coli | NCTC 11560 | TEM-1 β-lactamase producer |
| Staphylococcus aureus | NCTC 12493 | mecA positive, Methicillin resistant |
| Haemophilus influenzae | NCTC 12699 | Resistant to β-lactams (β-lactamase negative) |
Recommended in the UK Standards for Microbiology Investigations (QSOP 51i2.2)
Control strains for laboratory detection and reporting of bacteria with extended spectrum β-lactamases
| Organism | NCTC® Strain Reference | Characteristics |
| Escherichia coli | NCTC 13353 | CTX-M-15 (cefotaxime) |
| Escherichia coli | NCTC 13351 | TEM-3 (Broad Spectrum) |
| Escherichia coli | NCTC 13352 | TEM-10 (ceftazidimase) |
| Klebsiella pneumoniae | NCTC 13368 | SHV-18 ESBL producing |
| Escherichia coli | NCTC 10418 | Negative control |
EUCAST Recommended Strains for Internal QC (version 2.0)
| Organism | NCTC® Strain Reference |
| Escherichia coli | NCTC 12241 |
| Staphylococcus aureus | NCTC 12973 |
| Pseudomonas aeruginosa | NCTC 12903 |
| Enterococcus faecalis | NCTC 12697 |
| Haemophilus influenzae | NCTC 8468 |
| Streptococcus pneumoniae | NCTC 12977 |
US Clinical and Laboratory Standards Institute (CLSI)
Recommended performance standards for antimicrobial susceptibility testing (M100-S21)
| Organism | NCTC® Strain Reference | Characteristics | ATCC® Strain Ref |
| Enterococcus faecalis | NCTC 12697 | ATCC 29212 | |
| Escherichia coli | NCTC 12241 | β-lactamase negative | ATCC 25922 |
| Escherichia coli | NCTC 11954 | TEM-1 β-lactamase (Non-ESBL) producer | ATCC 35218 |
| Staphylococcus aureus | NCTC 12981 | β-lactamase negative, mecA negative | ATCC 25923 |
| Staphylococcus aureus | NCTC 12973 | Weak β-lactamase positive, mecA negative | ATCC 29213 |
| Staphylococcus aureus | NCTC 13373 | Oxacillin resistant, mecA positive | ATCC 43300 |
| Pseudomonas aeruginosa | NCTC 12903 | Contains inducible AmpC β-lactamase | ATCC 27853 |
| Haemophilus influenzae | NCTC 12699 | BLNAR (β-lactamase negative, ampicillin resistant) | ATCC 49247 |
| Streptococcus pneumoniae | NCTC 12977 | Penicillin intermediate (altered penicillin binding protein) | ATCC 49619 |
| Neisseria gonorrhoeae | NCTC 12700 | CMRNG (Chromosome-mediated resistant Neisseria gonorrhoeae) | ATCC 49226 |
| Bacteroides fragilis | NCTC 9343 | ATCC 25285 | |
| Klebsiella pneumoniae | NCTC 13368 | SHV-18 ESBL producing | ATCC 700603 |
| Helicobacter pylori | NCTC 11637 | ATCC 43504 |
Other Useful Websites
HPA Antimicrobial Resistance Monitoring and Reference Laboratory
British Society of Antimicrobial Chemotherapy (BSAC)
The European Committee on Antimicrobial Susceptibility Testing (EUCAST)
United States Clinical and Laboratory Standards Institute (CLSI)
UK Standards for Microbiological Investigations Methods
