A novel broadly applicable PCR-RFLP method for rapid identification and subtyping of H58 Salmonella Typhi.
Salmonella Typhi (S. Typhi), the human-adapted agent of typhoid fever, is genetically monomorphic. SNPs accumulation divided the S. Typhi population in 85 haplotypes (H) of which one, H58, has undergone a clonal expansion. The surveillance of H58 S. Typhi is particularly important, especially in areas where typhoid fever is endemic. We developed a simple PCR and PCR-RFLP method to detect and subtype H58 S. Typhi based on the presence of genomic deletion and specific SNPs. The method was validated against 39 S. Typhi isolates of known haplotype, showing 100% of specificity and high sensitivity, and then used to screen a collection of 99 S. Typhi from Asia, demonstrating a high incidence of H58 S. Typhi in Jordan and India. Our method is designed to be applied in all laboratories with basic molecular biology equipment and few financial resources and allows the surveillance of H58 S. Typhi in resource poor settings.
Department of Biomedical Sciences, University of Sassari, V. le San Pietro 43/B, 07100 Sassari, Italy. Electronic address: murgiam@uniss.it.
Manuela
M
Murgia
Department of Biomedical Sciences, University of Sassari, V. le San Pietro 43/B, 07100 Sassari, Italy; Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, PO Box 3354 (MBC-03), Riyadh 11211, Saudi Arabia. Electronic address: rubino@uniss.it.
Salvatore
S
Rubino
Norwich Medical School, Norwich Research NRE Park, University of East Anglia, Norwich NR4 7TJ, United Kingdom. Electronic address: j.wain@uea.ac.uk.
John
J
Wain
Department of Microbiology, Safdarjung Hospital and Assoc VMMC, New Delhi, India. Electronic address: rgaind5@hotmail.com.
Rajni
R
Gaind
Department of Biomedical Sciences, University of Sassari, V. le San Pietro 43/B, 07100 Sassari, Italy. Electronic address: biancap@uniss.it.
Bianca
B
Paglietti
D015373:Bacterial Typing Techniques / Q000379:methods*; D004269:DNA, Bacterial / Q000235:genetics; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D012485:Salmonella typhi / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D014435:Typhoid Fever / Q000382:microbiology
D004269:DNA, Bacterial
H58 identification; PCR-RFLP; Phylogenetic tree; S. Typhi; SNPs