Evaluation of PCR-based methods and ribotyping performed with a mixture of PstI and SphI to differentiate strains of Salmonella serotype Enteritidis

• Published in: Journal of medical microbiology Vol. 47; no. 5; pp. 427 - 434
• Main Authors: Landeras, Elena, Mendoza, M. Carmen
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Reading Soc General Microbiol 01-05-1998; Society for General Microbiology
• Subjects: Bacterial Typing Techniques - statistics & numerical data; Bacteriological methods and techniques used in bacteriology; Bacteriology; Bacteriophage Typing; Biological and medical sciences; Deoxyribonucleases, Type II Site-Specific; DNA, Bacterial - genetics; DNA, Ribosomal - genetics; Evaluation Studies as Topic; Fundamental and applied biological sciences. Psychology; Humans; Microbiology; Polymerase Chain Reaction - methods; Polymerase Chain Reaction - statistics & numerical data; Random Amplified Polymorphic DNA Technique - statistics & numerical data; Reproducibility of Results; Salmonella; Salmonella enteritidis - classification; Salmonella enteritidis - genetics; Salmonella enteritidis - isolation & purification; Salmonella Infections - microbiology; Sensitivity and Specificity; Serotyping; Performance evaluation; Polymerase chain reaction; Salmonella; Ribotype; Typing; Bacteria; Genotype; Method; Strain specificity; Enterobacteriaceae
• ISSN: 0022-2615; 1473-5644
• DOI: 10.1099/00222615-47-5-427

Área de Microbiología, Departamento de Biología Funcional, Universidad de Oviedo, 33006 Oviedo, Spain
Corresponding author: Professor M. C. Mendoza.
Received June 17, 1997
Accepted October 6, 1997
The capacity to differentiate Salmonella serotype Enteritidis strains by PCR ribotyping; RAPD typing with three arbitrary primers and ribotyping with a mixture of Pst I and Sph I or ‘PS ribotyping’, was evaluated on a series of 65 strains associated with human infections and 11 reference strains. The series had been analysed previously by phage typing and ribotyping performed with Pst I and Sph I, separately. All methods typed all the strains; however, only ribotyping showed good reproducibility and sensitivity. Twenty-two PS ribotypes (discrimination index = 0.74) were identified, differentiating strains ascribed to seven phage types (PTs 1, 4, 6, 6a, 7, 8 and RDNC) as well as phage untyped strains. Conversely, some strains of PTs, 1, 4, 5a, 6, 6a, 7, 34 and RDNC showed the most frequent PS ribotype. By PCR ribotyping a single profile was found; while by RAPD typing, one, two or three RAPD types were identified with the primers MK22, OPB6 and OPB17, respectively. All Spanish strains were assigned to a single combined RAPD type, except PT11 strains which showed a different and specific RAPD type with OPB17. The banding patterns defining the PS ribotypes were interpreted more easily and the patterns could be compared more accurately than the banding patterns defining RAPD types. A similarity dendrogram generated from the 22 PS ribotypes was traced and compared with RAPD types and phage types. Data from this work indicated that ‘PS ribotyping’ was the most useful genetic procedure to differentiate Enteritidis strains, and, therefore, it can be used as a complementary or alternative typing method to phage typing within this serotype.