A comparison of two PCR-based typing methods with pulsed-field gel electrophoresis in Salmonella enterica serovar Enteritidis

• Published in: International journal of medical microbiology 2009-08, Vol.299 (6), p.410-420
• Main Authors: Ross, Ian L, Heuzenroeder, Michael W
• Format: Article
• Language: English
• Subjects: Animals; Australia; Bacterial Typing Techniques - methods; Bacteriophage Typing; Cluster Analysis; DNA Fingerprinting - methods; Electrophoresis, Gel, Pulsed-Field - methods; Humans; Infectious Disease; MAPLT; Medical Education; MLVA; Molecular Epidemiology - methods; PFGE; Polymerase Chain Reaction - methods; Salmonella enterica; Salmonella Enteritidis; Salmonella enteritidis - classification; Salmonella enteritidis - genetics; Salmonella Infections - microbiology; Salmonella typhimurium; Sensitivity and Specificity
• ISSN: 1438-4221; 1618-0607
• DOI: 10.1016/j.ijmm.2008.12.002

Abstract Two novel molecular typing methods, multiple-locus variable-number tandem repeats (VNTR) analysis (MLVA) and multiple amplification of phage loci typing (MAPLT), were compared with pulsed-field gel electrophoresis (PFGE) for the discrimination of 128 Salmonella enterica serovar Enteritidis ( S . Enteritidis) isolates. Selected epidemiologically unrelated isolates represented a cross-section of phage types routinely isolated in Australia and included 28 isolates that could not be assigned a phage type. Targeting 5 previously described loci, MLVA generated 61 different profiles with a Simpson index of diversity of DI=0.968. MLVA locus STTR-5 proved to be the most diverse with 11 different alleles detected with a Nei's diversity index value of D =0.769. Using 8 MAPLT primers previously developed for S . Typhimurium produced 36 different profiles with a DI value of 0.948. By contrast, PFGE only generated 13 different pulsed-field patterns, DI=0.873. Within each phage type there was variation in the extent to which either molecular method was able to discriminate the S . Enteritidis isolates. MAPLT provided more discrimination in terms of the number of profiles and DI value for phage type 1 and the untypable strains while MLVA was more discriminatory for phage types 14var and 26. There was a general lack of concordance of either molecular assay to phage type. These results suggest that both MAPLT and MLVA have excellent potential as tools for epidemiological studies of S . Enteritidis.