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Find out what BrCAST is
What is BrCAST?
BrCAST is a national committee composed by indicated representatives by the Brazilian Society of Clinical Analyzes, Infectious Diseases, Microbiology and Clinical Pathology and Laboratory Medicine.
What is the purpose of BrCAST?
The main objective of BrCAST is to act in the standardization of antimicrobial sensitivity tests in accordance with the international standards of the European Committee on Antimicrobial Susceptibility Testing (EuCAST) and the Clinical and Laboratory Standard Institute (CLSI).
Why change to BrCAST?
According to BrCAST documentation, this change was adopted due to the need for a standardization of interpretation on antimicrobial sensitivity tests. These actions contribute to the proper prescription of antimicrobials and will assist in preventive and control measures for infectious and contagious diseases
When does BrCAST become mandatory?
The deadline for laboratories to adapt to the BrCAST methodology is 12 months, counting from the date of publication of Ordinance No. 64 of 12/11/2018 (deadline 12/18/2019) that “Determines the laboratories of the public and private network of all Federated Units, the use of interpretation standards for antimicrobial sensitivity tests (TSA), based on the Brazilian documents of the European Committee on Antimicrobial Susceptibility Testing ”.
Where can I find the BrCAST documentation?
All the necessary documentation for the implementation of BrCAST is available for free on the website www.BrCAST.org.br, translated to Portuguese and with pertinent observations to assist in the implementation.
Below are the main changes with the implementation of BrCAST:
- Standardized culture media for TSA:
Mueller-Hinton Agar;
Mueller-Hinton agar supplemented with defibrinated horse blood and β-NAD (MH-F);
Means for determining MIC by the micro-dilution method in cation-adjusted Mueller-Hinton broth (MHB);
MHB supplemented with horse lysed blood and β-NAD (MH-F broth).
| Microorganism | Medium |
| Enterobacteriaceae | MH agar |
| Psoudomonas spp. | MH agar |
| Stenotrophomonas maltophilia | MH agar |
| Acinetobacter spp. | MH agar |
| Staphylococcus spp. | MH agar |
| Enterococcus spp. | MH agar |
| Streptococcus groups A, B, C and G | MH-F agar |
| Streptococcus pneumoniae | MH-F agar |
| Streptococcus viridans group | MH-F agar |
| Microorganism | Medium |
| Haemophilus influenzae | MH-F agar |
| Moraxella catarrhalis | MH-F agar |
| Listeria monocytogenes | MH-F agar |
| Pasteurella multocida | MH-F agar |
| Campylobacter jejuni and coli | MH-F agar |
| Corynebacterium spp. | MH-F agar |
| Aerococcus sanguinicola and urinae | MH-F agar |
| Kingella kingae | MH-F agar |
| Others fastidious organisms | Pending |
Change in antibiotics concentration, as shown in the table below:
| Antibiotic discs | BrCAST concentration | CLSI concentration | Comments |
| Amoxicillin-clavulanate | 2-1µg | 2-10µg | Both dosages will be used. |
| Ampicillin | 2µg | 10µg | Both dosages will be used. |
| Ceftazidime | 10µg | 30µg | Only BrCAST concentration will be used. |
| Gentamicin | 30µg | 10µg | Both dosages will be used (120µg dosage will no longer be used). |
| Nitrofurantoin | 100µg | 300µg | Only BrCAST concentration will be used. |
| Penicillin | 01U | 10U | Only BrCAST concentration will be used. |
| Piperacillin-tazobactam | 30-6µg | 100-100µg | Only BrCAST concentration will be used. |
| Vancomycin | 5µg | 30µg | Only BrCAST concentration will be used. |
| Linezolid | 10µg | 30µg | Only BrCAST concentration will be used. |
| Cefotaxime | 5µg | 30µg | Only BrCAST concentration will be used. |
| Ceftaroline | 5µg | 30µg | Only BrCAST concentration will be used. |
| Incubation conditions for sensitivity test plates | |
| Microorganism | Incubation conditions |
| Enterobacteriaceae | 35±1ºC in air for 16-20h |
| Psoudomonas spp. | 35±1ºC in air for 16-20h |
| Stenotrophomonas maltophilia | 35±1ºC in air for 16-20h |
| Acinetobacter spp. | 35±1ºC in air for 16-20h |
| Staphylococcus spp. | 35±1ºC in air for 16-20h |
| Enterococcus spp. | 35±1ºC in air for 16-20h (24 hours for glycopeptides) |
| Streptococcus groups A, B, C and G | 35±1ºC in air with 4-6% CO for 16-20h |
| Streptococcus pneumoniae | 35±1ºC in air with 4-6% CO for 16-20h |
| Streptococcus viridans group | 35±1ºC in air with 4-6% CO for 16-20h |
| Haemophilus influenzae | 35±1ºC in air with 4-6% CO for 16-20h |
| Moraxella catarrhalis | 35±1ºC in air with 4-6% CO for 16-20h |
| Listeria monocytogenes | 35±1ºC in air with 4-6% CO for 16-20h |
| Pasteurella multocida | 35±1ºC in air with 4-6% CO for 16-20h |
| Campylobacter jejuni and coli | See appendix A |
| Corynebacterium spp. | 35±1ºC in air with 4-6% CO for 16-20h. Isolates with insufficient growth in 16-20h should be re-incubated immediately and the inhibition halos should be read after a total of 40-44h of incubation |
| Aerococcus sanguinicola and urinae | 35±1ºC in air with 4-6% CO for 16-20h. Isolates with insufficient growth in 16-20h should be re-incubated immediately and the inhibition halos should be read after a total of 40-44h of incubation |
| Kingella kingae | 35±1ºC in air with 4-6% CO for 16-20h. Isolates with insufficient growth in 16-20h should be re-incubated immediately and the inhibition halos should be read after a total of 40-44h of incubation |
| Others fastidious organisms | Pending |
- Halo size measures:
The Mueller Hinton Agar plates (not supplemented) must be placed on a dark surface with light positioned directly under the plate, and determine the inhibition halos with a calibrated (regular or caliper) ruler posicioned on the bottom of the plate;
Media with blood in its composition should be read after cover removal and the halo of inhibition, not the hemolysis, should be measured under the reflected light.
In the BrCAST diffusion disk manual there is more information relevant to the interpretation of the halos of antibiograms.
Steps for the implementation:
What does it take to start the implementation?
| Activity description | Period |
| Purchase planning for inputs – antibiotics, culture media and ATCC strains. | – |
| Start the validation process for new discs and culture media. • Start MH and new antibiotics • Start MH-F | 4 days. Perform 5 inoculations in the period of 4 days, totalizing 20 tests for each antibiotic tested. |
| Results evaluation of the validation process and final report. | – |
| Performance of Quality Control. Change levels for BrCAST standardization in Quality Control. | Weekly and/or every new batch. |
| Quality Control results evaluation. | Weekly and/or every new batch. |
| Use of clinical levels in the antibiogram profile. • Changing levels for germs when using MH. • Changing levels for germs when using MH-F. | Daily. |
How should the validation process of the new inputs be implemented?
Recommended strains for routine quality control
Escherichia coli ATCC 25922
Pseudomonas aeruginosa ATCC 27853
Staphylococcus aureus ATCC 29213
Enterococcus faecalis ATCC 29212
Streptococcus pneumoniae ATCC 49619
Haemophilus influenzae ATCC 49766
Campylobacter jejuni ATCC 33560
For the validation of new inputs, BrCAST defines an initial evaluation of 20 tests for each antimicrobial with a maximum of 10% unexpected results so the control can be carried out weekly.
RenyLab Diagnostics In Vitro wishes all customers and laboratories success in the implementation of BrCAST.
We sell the BRCAST Antibiogram Discs and Culture Media. Our technical team is available for inquiries.