Fluorescent amplified fragment length polymorphism genotyping of Salmonella Enteritidis: a method suitable for rapid outbreak recognition.
OBJECTIVE
To perform fluorescent amplified fragment length polymorphism (FAFLP) analysis on phage type (PT) reference strains of Salmonella enterica subsp. enterica serotype Enteritidis (S. Enteritidis), and S. Enteritidis PT 6 and 6a recent clinical isolates to determine its usefulness for primary characterization of clinical S. Enteritidis isolates, and then to determine whether FAFLP is suitable for rapid characterization of strains in an outbreak situation.


METHODS
Twenty-five PT reference strains of S. Enteritidis and 20 S. Enteritidis PT 6 and 6a clinical isolates were subjected to FAFLP analysis using the selective primer combinations Eco + 0-Mse + T and Eco + 0-Mse + TA.


RESULTS
FAFLP successfully separated each one of the 25 S. Enteritidis PT strains into distinct profiles, while macrorestriction and PFGE using XbaI identified 20 pulsed-field profiles. FAFLP also resolved cases and outbreaks due to S. Enteritidis PTs 6 and 6a.


CONCLUSIONS
The resolving power of FAFLP was higher than that of PFGE. FAFLP is a highly discriminatory genotyping method and, in conjunction with phage typing for primary subdivision of S. Enteritidis, provides a rapid and powerful tool for strain differentiation, both for outbreak investigation and for epidemiologic surveillance.
Scott
F
F
Molecular Biology Unit, Virus Reference Division, Central Public Health Laboratory, London, UK.
Threlfall
J
J
Stanley
J
J
Arnold
C
C
D015373:Bacterial Typing Techniques; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005453:Fluorescence; D005784:Gene Amplification; D005838:Genotype; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length; D015183:Restriction Mapping; D012480:Salmonella Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D012477:Salmonella enteritidis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification