UK NEQAS for Microbiology – Keeping Ahead of the Curve

Clinical microbiology is transforming at pace so a key challenge for UK NEQAS Scheme Organisers is to keep abreast of global developments. This helps ensure that the EQA service reflects not only changes in technology, the emergence of new pathogens and alterations to microbial classification and nomenclature, but also remains compliant with regulations about safety and pathogen categorisation and meets laboratories’ accreditation needs.

However, when it comes to test procedures, there is a balance to be struck between the ‘old’ and the ‘new’ and classical tests still have an important role to play in clinical diagnostic bacteriology. A recent study by US scientists of 26,429 cases of meningitis and encephalitis in infants¹ indicated that the most commonly requested test was the Gram stain, devised in 1882, yet despite its simplicity, requires a degree of expertise to interpret results correctly. The microbiologists who manufacture and quality control test the UK NEQAS EQA bacteriology samples frequently prepare and interpret Gram stains for a wide range of bacterial strains. Scientists in participating laboratories must also be competent if they are to report accurate results for samples because there is no doubt that correctly reported results for classical tests such as the Gram stain can improve patient outcomes.

Moving forward from 19^th century to 21^st century technologies, we recognise that pathogen genomics is now widely acknowledged as a powerful tool for investigating and managing infectious diseases. Public Health England was an early adopter in applying whole genome sequencing (WGS) to routine bacteriology service delivery, particularly in their national reference laboratory for gastrointestinal pathogens², and it is only a matter of time before this technology rolls into routine testing laboratories. The UK NEQAS EQA team are planning and preparing for this, appreciating also that new and different skills will be required.

Sequencing technology continues to reveal virulence factors in bacterial species that have not traditionally been associated with infection. Examples include Staphylococcus scheitzeri and S.argenteus which have been shown to possess genes for virulence factors normally associated with S.aureus³. Genomic characterisation of Streptococcus pseudopneumoniae, an overlooked pathogen emerging as the causative agent of lower respiratory tract infections, has identified multiple virulence factors in this species⁴. The important educational role of UK NEQAS schemes makes it essential that at least some EQA samples reflect these evolving trends.

Another question for our Organisers: “What’s in a name?” When it comes to microbiology the answer may well be “controversy and disagreement”. Taxonomists are rapidly reclassifying and renaming bacterial, virus and fungal strains as the switch from phenotypic to genotypic criteria challenges historical perceptions of relatedness. Microbial name changes present educational and communication challenges that EQA schemes can help to address since there is real possibility that a medical microbiologist may not recognise or appropriately treat a serious infection due to a name change. For this reason Lawson et al⁵ took great care to consider this issue when proposing the reclassification of Clostridium difficile as Clostridiodes difficile in 2015; the new name, which can still be abbreviated to C.diff, is only now starting to take precedence.

UK NEQAS EQA Scheme Organisers must use their knowledge, skills and professional networks to make sure that the EQA services support testing laboratories in reporting accurate, correctly interpreted results for every patient specimen in the changing world of clinical microbiology. That’s why they strive to keep ahead of the curve.