Volume 7, Number 2—April 2001
THEME ISSUE
4th Decennial International Conference on Nosocomial and Healthcare-Associated Infections
State of the Art
Molecular Approaches to Diagnosing and Managing Infectious Diseases: Practicality and Costs
Michael A. Pfaller
Table 4
Genotypic methods for epidemiologic typing of microorganismsa,b
| Method | Examples | Comments |
|---|---|---|
| Plasmid analysis | Staphylococci Enterobacteriaceae | Plasmids may be digested with restriction endonucleases Only useful when organisms carry plasmids |
| Restriction endonuclease analysis of chromosomal DNA with conventional electrophoresis | Enterococci Staphylococcus aureus Clostridium difficile Candida spp. | Large number of bands Difficult to interpret Not amenable to computer analysis |
| PFGE | Enterobacteriaceae Staphylococci Enterococci Candida spp. | Fewer bands Amenable to computer analysis Very broad application. |
| Genome restriction fragment length polymorphism analysis: ribotyping, insertion sequence probe fingerprinting | Enterobacteriaceae Staphylococci Pseudomonas aeruginosa Mycobacterium tuberculosis Candida spp. | Fewer bands Computer analysis Sequence-based profiles Automated |
| PCR-based methods: repetitive elements PCR spacer typing, selective amplification of genome restriction fragments, multilocus allelic sequence-based typing | Enterobacteriaceae Acinetobacter spp. Staphylococci M. tuberculosis HCV | Crude extracts and small amounts of DNA may suffice |
| Library probe genotypic hybridization schemes: multilocus probe dot-blot patterns, high-density oligonucleotide patterns | Burkholderia cepacia S. aureus M. tuberculosis | Unambiguous yes-no result Less discrimination than other methods Couple with DNA chip technology |
aThe table contains examples of available methods and applications and is not intended to be all-inclusive.
bAdapted from Pfaller (2).
