Molecular Epidemiology of Nosocomial Infection: Analysis of Chromosomal Restriction Fragment Patterns by Pulsed-Field Gel Electrophoresis

Abstract

The epidemiological analysis of nosocomial pathogens is a subject of long-standing clinical interest. In recent years, molecular techniques have received increasing attention as a means of analyzing epidemiological interrelationships, thus leading to use of the term molecular epidemiology. Since chromosomal DNA represents a fundamental molecule of cellular identity, there has been particular interest in assessing chromosomal similarity as a measure of epidemiological relatedness.One attractive approach has been to digest chromosomal DNA with restriction enzymes, resulting in a series of different sized fragments that form patterns when comparatively analyzed by agarose gel electrophoresis. In this context, differences in fragment patterns commonly are referred to as restriction-fragment length polymorphisms (RFLPs). Enzymes commonly used to cleave DNA typically recognize numerous sites within the bacterial chromosome. With such enzymes, restriction digestion of DNA from different bacterial isolates results in fragments that are too numerous to compare accurately after conventional agarose gel electrophoresis.

Guidelines for the control of glycopeptide-resistant enterococci in hospitals

“…95 These both need to be assessed more rigorously with GRE collections including those from outbreaks. In recent years, pulsed-field gel electrophoresis (PFGE) has become the method of choice for the epidemiological analysis of many types of nosocomial infection, 96,97 including GRE. 92 However, there are no universally agreed standard criteria for interpreting PFGE banding patterns and there are problems with inter-and intralaboratory reproducibility.…”

Characterization of cefotaxime-resistant Escherichia coli isolates from a nosocomial outbreak at three geriatric hospitals

“…This indicates that the transmission was due to a single epidemic strain. 26,27 The strain TUM1083 was isolated earlier than the other strains. These results suggested that strain TUM1083 was the origin of this outbreak.…”

The matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS)-based protein peaks of 4448 and 5302Da are not associated with the presence of Panton-Valentine leukocidin

“…PFGE was applied as a standardized method and interpreted as described earlier (Goering and Tenover, 1997). For MLST, the arcC, aroE, glpF, gmk, pta, tpi, and yqiL genes were amplified by PCR, sequenced, and compared with reference strains as previously described (Enright et al, 2000).…”