Novel disruptive antimicrobial susceptibility tests

Antibiotic drugs

Novel disruptive antimicrobial susceptibility tests (<2 hours) sets the bar higher for improved patient outcomes by allowing selection of cost effective and highest sensitivity antibiotics – first to allow rapid and appropriate treatment.

FASTinov developed rapid and reliable AST based upon flow cytometry in order to provide clinically-actionable results in up to two hours, instead of two days. The increasing emergence of resistance to antibiotics has led to less effective treatment of common bacterial infections.

The World Health Organisation (WHO) launched the first World Antibiotic Awareness Week (November 2015) drawing attention to the importance of correct use of antibiotics. Expanding multiple mechanisms can give rise to antimicrobial resistance among microbial populations while the selective pressure from antibiotic use can also provide a competitive advantage for mutated strains.

Thus, resulting resistant clones – e.g. MRSA USA 300, Escherichia coli ST131, and Klebsiella pneumoniae ST258 – have disseminated rapidly worldwide. This spread is highly facilitated by a cohort of multiple distinct factors, such as interspecies horizontal gene transmission, clustering of patients in hospitals, poor sanitation in less-developed communities and increasing frequency of global travel and trade.

The development of resistant bacterial or fungal clones is a serious and growing global threat, leading to escalating healthcare costs, treatment failures, and patient deaths. In order to effectively treat infections and determine whether they are caused by resistant pathogens, quick and accurate susceptibility testing is mandatory.

Time-consuming methods

Although novel and fast techniques are increasingly available for the bacterial identification, the determination of drug susceptibility still largely depends upon time-consuming methods. This is due to the need of in vitro culture of bacteria isolated from biological samples in the presence of various antibiotics; read-out is invariably performed by visualizing bacterial growth.

The current AST methodology has a turnaround time of at least 24 hours, and up to 48 hours may be needed in case of blood cultures. Such long waits for lab results often leads to delayed and inadequate treatment decisions. In addition, most current methods can only be initiated after the availability of pure microbial cultures, hence requiring a long time for isolation before performing AST.

Multiple studies on delayed antibiotic treatment show that this current strategy leads to longer hospital or intensive care stay and increased health care costs. Additionally, inadequate antibiotic treatment is one of the main causes for the emergence of drug-resistant bacterial strains. Data provided by the European Centre for Disease Prevention and Control (ECDC) indicates that drug-resistant bacteria are responsible for at least 400,000 cases of infection and 25,000 deaths in Europe annually.

Apart from the preventable deaths, such infections lead to extra healthcare costs and productivity losses amounting to at least €1.5 bn (~£1.3) per year. Resistance to antibiotics poses a serious threat to public health in Europe and in the rest of the world, which may soon jeopardise many daily medical procedures, e.g. conventional surgery, aggressive chemotherapy or transplants. Prompt treatment of bacterial infections with effective drugs is especially important; a fast and accurate AST method is urgently needed to achieve that goal, improving care of patients with invasive bacterial infections.

The solution

The main idea is to assess early cell lesions produced by the antimicrobial drugs on microorganisms using flow cytometry. This technology is well known and used daily in clinical labs, but never applied to microbiology. This disruptive technology is not growth-dependent, thus requiring a shorter analytical time-period. After one hour of incubation with the main antibiotics and related fluorescent probes, it is possible to discriminate the different phenotypes – susceptible, intermediate or resistant – due to the predictable staining of the microbial cells.

Microbial cell disturbances such as membrane lesion, depolarisation imbalance or metabolic disturbances are used to correlate with susceptibility phenotypes. A susceptibility report in useful time will reduce the unnecessary use of broad spectrum or last line antibiotics; the quick detection of resistance could save lives and avoid the spread of dangerous microorganisms. Such a test will enable clinicians to start optimal targeted antibiotic treatment as soon as possible, with a major impact on health and quality of life of patients and on health care costs.

The company: meet FASTinov

FASTinov is a spin-off of Porto University, founded by a medical microbiologist and an intensive care specialist in 2013 in order to transfer the technology to the market. They understand patient needs, since they still work in parallel at a large university hospital and as researchers.  Two Portuguese capital venture companies Armilar and Busy Angels financed the company in 2014. The company is now a SA with headquarters at UPTEC, Porto. Last year FASTinov obtained the ISO 9001 certificate and next year intend to have ISO 13485.

FASTinov AST panels allow the evaluation of the antibacterial susceptibility profile within 1-2 h directly from positive blood cultures or from pure cultures, versus the classic 48 hours required by the current conventional methods. Three panels, one for gram negative, another for gram positive and another for the detection of main mechanisms of resistance will be CE/IVD marked by end of 2019.

The tests will be marketed as a microplate-based kit, containing ready to use panels of antibiotics and compatible probes to determine the effect of the antibiotics, instruction for use and a validated CE-IVD software package for interpretation of results.

FASTinov AST panels are presently under validation in a reference lab at Hospital Ramon et Cajal in Madrid, under Prof. Rafael Canton, an international reference expert in the field of AST.  New validation sites are being prepared for FDA submission through 2021. There are three panels:

FASTinov gramneg®

For Enterobacterales, Pseudomonas aeruginosa and Acinetobacter baumannii complex. It includes: ampicillin, amoxacillin/clavulanic acid, piperacillin/tazobactam, ceftazidime, cefotaxime, cefepime, ceftolozane/tazobactam, ciprofloxacin, gentamicin, amikacin, meropenem, imipenem and colistin.

FASTinov grampos®

For Staphylococcus spp and Enterococcus spp. It includes penicillin, ampicillin, cefoxitin, oxacillin, ampicillin, imipenem, gentamicin, vancomycin and linezolid.


For detection of main mechanisms of resistance: ESBL, carbapenemases and each type, KPC, metallocarbapenemase and OXA-like 48 and AmpC.


A patent for this technology was granted in Europe and USA. FASTinov received support from both P2020 and H2020, leading a consortium on the programme FAST-track to innovation. Several other products are in development or ready to validate such as AST panels for other microorganisms: fastidious microorganisms such as Haemophilus influenzae, Streptococcus pneumoniae, anaerobes and yeasts; for other biological products such as: urine or spinal fluid. Additionally, a veterinary AST panel is under development.

The microbiology AST market is around $3bn (~£2.3bn) with BioMerieux, Beckman Coulter, Thermo-fisher and BD as the main players. All have automatic solutions based upon the detection of microbial growth. Molecular assays are very useful but only can detect what is already known and it will be very difficult to obtain a full AST assay. New tools such as mass spectrometry have been developing although the result perspective is quite similar to what happens with molecular assays. Research methods are under development but too far away from the market.

Antimicrobial susceptibility tests are usually divided in phenotypic and genotypic assays. Due to the complexity of drug resistance and the limited prior knowledge of their molecular mechanisms, phenotypic methods are preferred. This means that in such assays we are evaluating the behaviour of the microorganism in the presence of the drug; the inconvenience regards the long time that they usually take. Genotypic tests are more rapid but only detect previously known genes that are related with resistance; its absence cannot be assumed as susceptibility and this is very relevant information for the management of antimicrobial therapy.

FASTinov AST assays combine the advantages of both perspectives: Despite being phenotypic – assessment of the cell lesions produced on the microorganisms following short incubation with the antibiotics, turning it in a rapid assay (<2 hours).


Cidália Pina Vaz

CEO & Co-founder


(+351) 924 393 147

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