The UK Health Security Agency’s (UKHSA) National Collection of Type Cultures (NCTC), offers a wide range of strains that can be used as controls in antimicrobial susceptibility testing to monitor test performance and quality of the materials used, and confirm that the in-use method will detect resistance.
NCTC strains are verified by the UK Health Security Agency’s Antimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, Gastrointestinal Bacteria Reference Unit (GBRU) and Anaerobic Reference Unit (ARU), and are used in diagnostic testing laboratories worldwide.
The strains (including equivalents) listed are specifically recommended by one or more of the following:
- European Committee on Antimicrobial Susceptibility Testing (EUCAST)
- Clinical and Laboratory Standards Institute (CLSI)
- United Kingdom Standards for Microbiology Investigations (UKSMI)
In addition, the collection also includes the WHO N. gonorrhoeae reference strain panel and a positive control strain panel for the validation of commercial assays for the detection of acquired carbapenemases.
AMR susceptibility control strains
1. The European Committee on Antimicrobial Susceptibility Testing (EUCAST)
The European Committee on Antimicrobial Susceptibility Testing (EUCAST) develops internationally recognised standards and clinical breakpoints for antimicrobial susceptibility testing. Its guidance helps laboratories accurately determine bacterial susceptibility to antibiotics, supporting effective patient care, antimicrobial stewardship, and consistent testing practices worldwide.
Routine and extended internal quality control for MIC determination and/or disk diffusion as recommended by EUCAST. Version 10.0, 2020
|
Organism
|
NCTC®
Strain Reference
|
Routine or extended internal QC
|
Characteristics
|
Other Collection Number
|
|
Campylobacter jejuni
|
NCTC 11351
|
Routine
|
|
ATCC 33560;
CCUG 11284;
CIP 702;
DSM 4688
|
|
Enterococcus faecalis
|
NCTC 12697
|
Routine
|
|
ATCC 29212;
WDCM 00087
|
|
NCTC 13379
|
Extended
|
High-level gentamicin resistant (HLGR), vanB-positive
|
ATCC 51299;
CIP 10467;
WDCM 00085;
WDCM 00152
|
|
Escherichia coli
|
NCTC 11954
|
Routine
|
TEM-1 β-lactamase (Non- ESBL) producer
|
ATCC 35218
|
|
NCTC 12241
|
Routine
|
|
ATCC 25922;
DSM 1103;
NCIMB 12210;
WDCM 00013
|
|
NCTC 13846
|
Routine
|
mcr-1 positive
|
DSM 105182
|
|
Haemophilus influenzae
|
NCTC 12699
|
Extended
|
|
ATCC 49247
|
|
 NCTC 12975
|
Routine
|
|
ATCC 49766;
CIP 103570
|
|
Klebsiella pneumoniae
|
NCTC 13368
|
Routine and Extended
|
SHV-18 ESBL-producing
|
ATCC 700603;
CCUG 45421;
LMG 20218
|
|
Mannheimia haemolytica
|
NCTC 9380
|
Routine
|
|
ATCC 33396;
DSM 10531;
CCUG 12392
|
|
Pseudomonas aeruginosa
|
NCTC 12903
|
Routine
|
|
ATCC 27853;
WDCM 00025
|
|
Staphylococcus aureus
|
NCTC 12493
|
Extended
|
Methicillin-resistant (MRSA),
mecA-positive
|
WDCM 00212
|
|
NCTC 12973
|
Routine
|
Weak β-lactamase positive,
mecA-negative
|
ATCC 29213;
CIP 103429;
DSM 2569;
JCM 2874;
WDCM 00131
|
|
Streptococcus pneumoniae
|
NCTC 12977
|
Routine
|
Susceptible to increased exposure to penicillin. (altered penicillin-binding protein)
|
ATCC 49619;
CIP 104340
|
2. Clinical and Laboratory Standards Institute (CLSI)
Clinical and Laboratory Standards Institute (CLSI) is a global, not-for-profit organization that develops consensus-based standards and guidelines for laboratory testing, including antimicrobial susceptibility testing (AST). CLSI standards help laboratories produce accurate, reliable, and standardized results to support effective patient care and antimicrobial stewardship worldwide.
Strains and equivalent strains recommended for CLSI M100 ED30:2020 Performance Standards for Antimicrobial Susceptibility Testing, 30th Edition Appendix C.
|
Organism
|
NCTC®
Strain Reference
|
Characteristics
|
Other Collection Number
|
|
Acinetobacter baumannii
|
NCTC 13304
|
OXA-27, OXA-23-like, OXA-51-like carbapenemases
|
|
|
Bacteroides fragilis
|
NCTC 9343
|
β-lactamase positive
|
ATCC 25285;
DSM 2151
|
|
Bacteroides thetaiotaomicron
|
NCTC 13706
|
β-lactamase positive
|
|
|
Enterococcus faecalis
|
NCTC 12697
|
|
ATCC 29212;
WDCM 00087
|
|
NCTC 13379
|
Resistant to vancomycin (VanB) and high- level aminoglycosides
|
ATCC 51299; CIP 10467; WDCM 00085; WDCM 00152
|
|
NCTC 13763
|
|
ATCC 33186;
WDCM 00210
|
|
Escherichia coli
|
NCTC 11954
|
Contains plasmid-encoded TEM-1 β- lactamase (Non-ESBL) producer
|
ATCC 35218
|
|
NCTC 12241
|
β-lactamase negative
|
ATCC 25922;
DSM 1103;
NCIMB 12210;
WDCM 00013
|
|
NCTC 13353
|
CTX-M-15 ESBL-producing strain
|
|
|
Haemophilus influenzae
|
NCTC 12699
|
BLNAR (β-lactamase negative, ampicillin resistant)
|
ATCC 49247
|
|
NCTC 12975
|
Ampicillin susceptible
|
ATCC 49766;
CIP 103570
|
|
NCTC 13377
|
|
ATCC 10211;
CIP 103708
|
|
Klebsiella pneumoniae
|
NCTC 13368
|
SHV-18 ESBL-producing strain
|
ATCC 700603;
CCUG 45421;
LMG 20218
|
|
Klebsiella pneumoniae
|
NCTC 13809
|
KPC-producing strain
|
ATCC BAA- 1705
|
|
NCTC 13810
|
Resistant to carbapenems by mechanisms other than carbapenemase activity
|
ATCC BAA- 1706
|
|
Neisseria gonorrhoeae
|
NCTC 12700
|
CMRNG (Chromosome-mediated resistant Neisseria gonorrhoeae)
|
ATCC 49226
|
|
Pseudomonas aeruginosa
|
NCTC 12903
|
Contains inducible AmpC β-lactamase
|
ATCC 27853;
WDCM 00025
|
|
Staphylococcus aureus
|
NCTC 12973
|
Weak β-lactamase positive, mecA-negative
|
ATCC 29213;
CIP 103429;
DSM 2569;
JCM 2874;
WDCM 00131
|
|
NCTC 12981
|
β-lactamase negative, mecA negative
|
ATCC 25923;
CIP 76.25;
DSM 1104;
JCM 2413;
WDCM 00034
|
|
NCTC 13373
|
Oxacillin resistant, mecA positive
|
ATCC 43300;
WDCM 00211
|
|
NCTC 13811
|
Contains inducible erm(A)-mediated resistance
|
ATCC BAA- 977
|
|
NCTC 13812
|
Contains msr(A)-mediated macrolide-only resistance
|
ATCC BAA- 976
|
|
NCTC 13813
|
High-level mupirocin resistance mediated by the mupA gene
|
ATCC BAA- 1708
|
|
Streptococcus pneumoniae
|
NCTC 12977
|
Penicillin intermediate (altered penicillin-binding protein)
|
ATCC 49619;
CIP 104340
|
3. UK Standards for Microbiology Investigations (UKSMI)
UK Standards for Microbiology Investigations (UK SMI) are a comprehensive collection of evidence-based laboratory standards, procedures, and diagnostic algorithms developed to support clinical microbiology practice in the UK. They promote high-quality, consistent investigation of infectious diseases and help laboratories deliver accurate, reliable, and standardised results.
Recommended in B59: Enterobacterales producing extended-spectrum β-lactamases.
|
Organism
|
NCTC®
Strain Reference
|
Characteristics
|
Other Collection Number
|
|
Escherichia coli
|
NCTC 13351
|
TEM-3 (broad spectrum ESBL)
|
|
|
NCTC 13352
|
TEM-10 (ceftazidimase, less active against cefotaxime)
|
|
|
NCTC 13353
|
CTX-M-15 (cefotaximase, less active against ceftazidime)
|
|
Klebsiella pneumoniae
|
NCTC 13368
|
SHV-18 ESBL-producing
|
ATCC 700603; CCUG 45421; LMG 20218
|
Note: Either E. coli NCTC 10418 or ATCC 25922 (NCTC equivalent = NCTC 12241) should be used as a negative control in ESBL confirmation tests.
Recommended in B60: Detection of bacteria with carbapenem-hydrolysing β-lactamases (carbapenemases)
|
Organism
|
NCTC®
Strain Reference
|
Characteristics
|
Other Collection Number
|
|
Class A Carbapenemase
|
|
Klebsiella pneumoniae
|
NCTC 13438
|
Member of the international ST258 clone producing KPC-3 carbapenemase
|
|
|
Class B Carbapenemases (Metallo-β-lactamases)
|
|
Escherichia coli
|
NCTC 13476
|
IMP-type metallo-carbapenemase (unsequenced)
|
CCUG 68729
|
|
Klebsiella pneumoniae
|
NCTC 13439
|
VIM-1 metallo-carbapenemase; QnrS1 (outbreak strain)
|
|
|
NCTC 13440
|
VIM-1 metallo-carbapenemase; QnrS1 (sporadic)
|
|
|
NCTC 13443
|
New Delhi Metallo-β-lactamase (NDM-1)
|
CCUG 68728
|
|
Pseudomonas aeruginosa
|
NCTC 13437
|
VIM-10 metallo-carbapenemase; VEB-1 ESBL
|
|
|
Class D Carbapenemases (OXA carbapenemases)
|
|
Acinetobacter baumannii
|
NCTC 13301
|
OXA-23 (also with OXA-51-like)
|
|
|
NCTC 13302
|
OXA-25 (OXA-24/40-like)
(also with OXA- 51-like)
|
|
|
NCTC 13303
|
OXA-26 (also with OXA-51-like)
|
|
|
NCTC 13304
|
OXA-27 (also with OXA-51-like)
|
|
|
NCTC 13305
|
(A 15) OXA-58 (also with OXA-51-like)
|
|
|
NCTC 13420
|
SE Clone OXA-51-like
|
|
|
NCTC 13421
|
OXA-23 Clone 2 (also with OXA-51-like)
|
|
|
NCTC 13422
|
NW Clone OXA-51-like
|
|
|
NCTC 13423
|
T strain (UK3) OXA-51-like
|
|
|
NCTC 13424
|
OXA-23 Clone 1 (also with OXA-51-like)
|
|
|
Klebsiella pneumoniae
|
NCTC 13442
|
Sequence type 353 with OXA-48
|
CCUG 68727
|
Note: Either E. coli NCTC 10418 or ATCC 25922 (NCTC equivalent = NCTC 12241) should be used as a negative control in confirmation tests.
4. World Health Organisation (WHO) - Neisseria gonorrhoeae panel
Antimicrobial Resistance (AMR) in N. gonorrhoeae is of significant international concern. Several high profile bodies (ECDC, CDC, WHO) have issued both global and regional action plans which aim to ensure that gonorrhoea remains a treatable infection. A consistent theme within of all the recommendations is the strong emphasis on AMR surveillance of N. gonorrhoeae isolates to monitor regional trends and to detect new and emerging resistance. However, the lack of a gold standard phenotypic AMR method for N. gonorrhoeae can present a challenge for laboratories and also make data comparisons between different laboratories difficult.
In order to address this, a set of 14 well-characterised WHO N. gonorrhoeae reference strains have been described and deposited within NCTC by Dr. Magnus Unemo from the WHO Collaborating Centre in Orebro, Sweden. This panel contains strains which display examples of all sensitive and resistant phenotypes to antimicrobials (current and historic) that have been used to treat gonorrhoea. All the strains have full reference genomes available and have been extensively characterised (MLST, NG-MAST type, plasmid status etc.). It is envisaged that they will be invaluable quality control strains for any laboratory undertaking either molecular diagnostics and/or AMR testing on N. gonorrhoeae isolates for surveillance or individual patient management purposes.
Neisseria gonorrhoeae strains are listed in the table below. DNA is available for all strains.
World Health Organisation (WHO) - Neisseria gonorrhoeae panel
|
Organism
|
NCTC®
Strain Reference
|
WHO
Designation
|
Characteristics
|
Other Collection Number
|
|
Neisseria
gonorrhoeae
|
NCTC 13477
|
WHO F
|
Fully susceptible isolate
|
CCUG 57595
|
|
NCTC 13478
|
WHO G
|
Resistant to ciprofloxacin (low-level), penicillin (intermediate) tetracycline (TRNG)
|
CCUG 57596
|
|
NCTC 15081
|
WHO H
|
|
|
|
NCTC 13479
|
WHO K
|
Resistant to cefixime (low-level), ciprofloxacin (high-
level), penicillin G,
tetracycline
|
CCUG 57597
|
|
NCTC 13480
|
WHO L
|
Resistant to azithromycin (intermediate), penicillin G,
ceftriaxone (low-level),
ciprofloxacin (high-level),
tetracycline
|
CCUG 57598
|
|
NCTC 13481
|
WHO M
|
Resistant to ciprofloxacin, penicillin G (penicillinase-
producing), tetracycline
|
CCUG 57599
|
|
NCTC 13482
|
WHO N
|
Resistant to penicillin G (penicillinase-producing),
ciprofloxacin, tetracycline
|
CCUG 57600
|
|
NCTC 13483
|
WHO O
|
Resistant to penicillin G (penicillinase-producing),
spectinomycin, tetracycline
|
CCUG 57601
|
|
NCTC 13484
|
WHO P
|
Resistant to azithromycin, penicillin G (intermediate),
tetracycline (intermediate)
|
CCUG 57602
|
|
NCTC 14208
|
WHO Q
|
Resistant to ceftriaxone (high-level), penicillin,
azithromycin (high-level),
ciprofloxacin, tetracycline
|
|
|
NCTC 15082
|
WHO R
|
|
|
|
NCTC 15083
|
WHO S2
|
|
|
|
NCTC 13817
|
WHO U
|
Resistant to azithromycin, ciprofloxacin (high-level),
penicillin G (intermediate),
tetracycline (intermediate)
|
|
|
NCTC 13818
|
WHO V
|
Resistant to azithromycin (high-level), ciprofloxacin
(high-level), penicillin G
(penicillinase-producing),
tetracycline
|
|
|
NCTC 13819
|
WHO W
|
Resistant to cefixime (low-level), ciprofloxacin (high-level), penicillin G, tetracycline
|
|
|
NCTC 13820
|
WHO X
|
Resistant to azithromycin (intermediate). Cefixime (high-level), ceftriaxone (high-level), ciprofloxacin (high-level), penicillin G
|
|
|
NCTC 13821
|
WHO Y
|
Resistant to azithromycin, cefixime (high-level), ceftriaxone (high-level) and ciprofloxacin (high-level), penicillin G, tetracycline
|
|
|
NCTC 13822
|
WHO Z
|
Resistant to azithromycin, ceftriaxone (low-level), cefixime (high-level) and ciprofloxacin (high-level), penicillin G, tetracycline
|
|
5. Positive Control Strains for the Validation of Commercial Assays for the Detection of Acquired Carbapenemases
The UK Health Security Agency’s Guidance Document (GW-427) “Commercial Assays for the Detection of Acquired Carbapenemases” provides evidence-based guidance for the selection and validation of one or more commercially available methods for the detection of carbapenemase-producing Gram-negative bacteria. The below strains cover the common and epidemiologically significant KPC, OXA-48-like, NDM, VIM and IMP carbapenemase gene variants known to be circulating in the UK and elsewhere.
Validation of commercial assay (carbapenems)
|
Organism
|
NCTC® Strain Reference
|
Characteristics
|
|
Escherichia coli
|
NCTC 14320
|
KPC non-metallo-carbapenemase IMP metallo-carbapenemase
OXA-48-like non-metallo-carbapenemase
|
|
NCTC 14321
|
KPC non-metallo-carbapenemase
OXA-48-like non-metallo-carbapenemase
|
|
NCTC 14324
|
OXA-484 non-metallo-carbapenemase
|
|
NCTC 14325
|
NDM-7 metallo-carbapenemase
|
|
NCTC 14329
|
OXA-244 non-metallo-carbapenemase
|
|
NCTC 14333
|
NDM-4 metallo-carbapenemase
|
|
NCTC 14338
|
OXA-48 non-metallo-carbapenemase
|
|
NCTC 14339
|
NDM-5 metallo-carbapenemase
|
|
Enterobacter cloacae complex
|
NCTC 14322
|
KPC-4 non-metallo-carbapenemase
|
|
NCTC 14326
|
VIM-1 metallo-carbapenemase
|
|
NCTC 14328
|
VIM-4 metallo-carbapenemase
|
|
NCTC 14336
|
KPC-2 non-metallo-carbapenemase
|
|
Klebsiella pneumoniae
|
NCTC 14323
|
NDM-1 metallo-carbapenemase
OXA-48 non-metallo-carbapenemase
|
|
NCTC 14327
|
KPC-3 non-metallo-carbapenemase
|
|
NCTC 14330
|
OXA-181 non-metallo-carbapenemase
|
|
NCTC 14331
|
NDM-1 metallo-carbapenemase
|
|
NCTC 14332
|
NDM-1 metallo-carbapenemase
OXA-232 non-metallo-carbapenemase
|
|
NCTC 14334
|
IMP-4 metallo-carbapenemase
|
|
NCTC 14335
|
OXA-232 non-metallo-carbapenemase
|
|
NCTC 14337
|
IMP-1 metallo-carbapenemase
|
