How to Select and Interpret Molecular Strain Typing Methods for Epidemiological Studies of Bacterial Infections A Review for Healthcare Epidemiologists

Abstract

Strain typing is an integral part of epidemiological investigations of nosocomial infections. Methods for distinguishing among bacterial strains have improved dramatically over the last 5 years, due mainly to the introduction of molecular technology. Although not all molecular techniques are equally effective for typing all organisms, pulsed-field gel electrophoresis is the technique currently favored for most nosocomial pathogens. Criteria to aid epidemiologists in interpreting results have been published. Nucleic acid amplification-based typing methods also are applicable to many organisms and can be completed within a single day, but interpretive criteria still are under debate. Strain typing cannot be used to replace a sound epidemiological investigation, but serves as a useful adjunct to such investigations.

Detection of plasmid-mediated AmpC β-lactamase in Escherichia coli and Klebsiella pneumoniae

“…The DNA band profi les were analysed with Bio-1D ++ (UPGMA) software (Bio-Rad Laboratories, Nazareth, Belgium) program coeffi cient with Nei and Li Dice. The results of band patterns were evaluated according to criteria of Tenover et al, [16] and the strains were classifi ed as indistinguishable, closely related, possible related, or different.…”

Global transmission of prolyliminopeptidase-negative Neisseria gonorrhoeae strains: implications for changes in diagnostic strategies

“…9 In the PFGE, isolates were considered indistinguishable if no band differed in any of the fingerprints (identical PFGE type, eg, A,a); closely or possibly related if 1-6 bands differed in any of the fingerprints (variant of the same PFGE type, eg, A1,a); and different if a difference in >7 bands was documented in any of the fingerprints (eg, C,c). 19 In the opa-typing, isolates were considered to have indistinguishable opa-types if they differed by (1 band. NG-MAST was performed on the 44 selected isolates and on the 29 isolates from the earlier study 9 as described previously.…”

Molecular Characterization of Carbapenem-Resistant Klebsiella pneumoniae Species Isolated From a Tertiary Hospital, Ankara, Turkey

“…Although WGS has ultimate resolution and is already used for the molecular typing of many microorganisms in developed countries, it is still too laborious and time-consuming to obtain useful data in routine surveillance (15). Currently, among the DNA fingerprinting methods, PFGE is a worldwide used reliable, discriminative, and reproducible method for a variety of bacterial species including K. pneumoniae (16)(17)(18).…”