10. Conclusions and future perspectives
During the last two decades numerous rapid methods for the
identification of foodborne bacteria have been developed. Although
cultivation techniques suffer from several drawbacks, their
importance remains high because rapid methods continue to have
limitations. Innovative techniques and methodical improvements
have boosted the potential of FISH to detect foodborne pathogens
although many of these beneficial advancements have not yet been
adequately transferred to the routine use of FISH in food microbiology.
The need for efficient pathogen concentration and separation
from the food matrix to overcome or minimize cultural preenrichment,
the pivotal implementation of high-performance
modular systems for automated FISH analyses and the establishment
of standardized protocols are future challenges, which have to
be further addressed.
Table 3
Summary of strengths and weaknesses of the conventional techniques, FISH and PCR-derived techniques.
Test feature Conventional microbiological
detection
FISH PCR-derived techniques
Detection principle/test target Pathogen multiplication,
metabolic traits
Binding to bacterial rRNA (mRNA, DNA) Amplification of bacterial
DNA or RNA
Test speed þ þþ
Specificity þ þþ þþ
Sensitivity (Jasson et al., 2010) þþ (1 CFU/25 g) þ (without enrichment, manual
microscopic evaluation)
þþ (real-time PCR)
Exclusion of dead material Yes Yes No
Detection of VBNC bacteria No Yes (Yes)
Bacterial load estimation þ þ ±
Robustness/matrix dependency þþ ± ±
Multiplex feasibility þ þ
Costs per test ± ± þ
Test complexity þ ± ±
Potential for standardization þ ± (without automation) þ
Current state of validation and
implementation
þþ þ
Potential for high-throughput analyses þ þþ
Potential for routine testing, monitoring
and risk assessment
þ þ þ
þþ: excellent, þ: good, ±: ambiguous, : poor, : severe weakness.