Microbiology without culture - is this the future? Professor Brian Duerden Inspector of Microbiology and Infection Control, Department of Health

Historical perspective 1850 – 1900 –1850s: Pasteur; liquid culture – s Koch: solid media –1894 Gram’s stain 1900 – 1980 –Serotyping; phage typing –DNA discovered 1980s Biochemical analyses –Metabolic products (GLC) –Proteins – whole cell; cell wall (SDS-PAGE) –Whole cell (pyrolysis) All needed culture first

1990s – age of immediacy! Rapid tests Same day results Short turnaround times Immediate answers Point of care (POC) testing And automation; computerisation ………non-culture methods ………non-culture methods

Methods Molecular detection – nucleic acid –Probes –PCR Antigen detection......who does the tests? where are they done? where are they done?

Why are we doing the tests? Cost?Diagnosis –Guide treatment Antibiotic or not? Which? eg. GpA streptococcus –Start infection prevention and control action –Take public health actions Screening for carriage/colonisation –Infection control & public health actions –Prophylaxis (eg. GpB streptococcus) Speed is of the essence

How urgent are the answers? Primary care –While the patient is there? –Organisation? STDs – GUM clinics; strong history –Now in pharmacies??? Public health – TB –Days not hours Healthcare Associated Infections (HCAI) –Treatment; isolation; infection control action

NB. Primary culture then non-culture? Identify organisms in primary cultures –Rapid non-culture methods –Probes; PCR; rRNA –Resistance genes How vital? –Blood cultures –Early CORRECT antibiotic improves survival –But will clinicians change antibiotic?

MRSA screening DH requirement – all admissions to be screened before or on admission –All elective admissions by March 2009 Includes day cases Not ophthalmic day cases; not maternity –All admissions asap, at latest by March 2011 Methods – conventional culture; rapid; automated? –Needs clinical organisation; ability to take action –Laboratory? Point of admission? Pre-admission clinic?

C. difficile diagnosis DH target – 30% reduction by –Baseline : c. 60,000 –SHA and PCT targets based on population Standardised to 8.4 cases per 10,000 as target –Acute trust targets within PCT packages Standardised to admissions Surveillance figures depend upon accurate diagnosis Infection control actions depend upon rapid results in all healthcare settings Methods: toxin detection (A+B); +/- antigen?

Norovirus Major cause of ward closure Respond to clinical diagnosis –Isolation; cohorting; closed to admissions –Staff restrictions (cohorting) –Cleaning and disinfection Quick confirmation needed to reassure actions Not every case needs testing

Pandemic (or seasonal) flu? Primary care –Confirm diagnosis for antiviral use? Current policy –Diagnose on clinical grounds when flu known to be circulating –Keep infected patients away from GP surgeries

Cautionary tales Loss of epidemiological and surveillance data Antimicrobial susceptibility data? POC – whose responsibility Quality and standards Serendipity

Loss of data Antimicrobial susceptibility –Few non-culture tests Epidemiology –Typing Can it be done on non-culture testing? Most needs the isolate Surveillance –POC – loss of data Unless systems linked to reporting systems

POC testing Who does it? –What training? Who assesses competence? –Who manages them? Equipment maintenance –Who is responsible? QC and QA? Links to the laboratory Reporting system? Accreditation?

Quality issues Quality control –Records; links to laboratories EQA –NEQAS programmes? Accreditation –CPA; UKAS

Current developments POC Accreditation –Pathology modernisation project –Working with UKAS Benchmarking –Primary care use of Pathology services –Keele team –Microbiology pilots soon –??? Impact of POC; rapid results

Serendipity What could be causing that? I would not have thought of that? We don’t have a DNA probe for that! Where is experience, ‘nose’, knowledge? With non-culture tests ……..you only find what you know you are looking for