In clinical microbiology, pathogen cultivation is still the gold standard in diagnostic procedures. Relevant culturing techniques, however, both in virology and in bacteriology, require long incubation periods that are incompatible with the clinical management of patients who are often seriously ill.
The introduction of molecular biological techniques that allow a microbiological diagnosis within a few hours has therefore revolutionised the diagnostics of infectious diseases.
In addition, sequence analysis of highly conserved genes (16S rDNA genes) allows clinical samples to be tested without a priori information about the suspected pathogen. This also applies to the use of modern mass spectrometric techniques (MALDI-TOF), which only took a few years to find their way into the diagnostic algorithms of numerous medical laboratories, for testing culture material.
It is already becoming apparent that in a few years' time it will be possible to completely analyse cultured isolates or even clinical samples within a few hours using state-of-the art full genome analyses.
Whether these methods will help to entirely replace phenotypic analysis remains to be seen.
In certain suspected clinical diagnoses or when analysing suspected cases of bioterrorism, it makes sense to check for several potential pathogens at the same time. The use of validated methods that can identify eight to ten different pathogens provides valid results within two hours.
16S and 23S rDNA Analysis
After applying a validated DNA extraction method, the sequencing of highly conserved genes reliably identifies a pathogen within a few hours.
Over the last three years, certified mass spectrometry techniques (MALDI-TOF) have become the main methods for species identification in clinical microbiology. By generating data sets from numerous bacterial strains associated with biothreats, the databases required for the matching of profiles of unknown isolates has been expanded to the extent that all such pathogens can now be identified.
Full genome analysis
Especially in time-critical situations or situations that are relevant to public health (outbreaks), full genome analysis will play an important role in future. Providing the necessary technical platform and relevant bioinformatic expertise therefore has high priority within this focus of research.