Shigellosis is one of the major public health concerns in developing and low-income countries caused
by four species of Shigella. There is an apparent need to develop rapid, cost-efective, sensitive and
specifc methods for diferentiation of Shigella species to be used in outbreaks and health surveillance
systems. We developed a sensitive and specifc Fourier-transform infrared spectroscopy (FTIR) based
method followed by principal component analysis (PCA) and hierarchical clustering analysis (HCA)
assays to diferentiate four species of Shigella isolates from stool samples. The FTIR based method
was evaluated by diferentiation of 91 Shigella species from each other in clinical samples using both
gold standards (culture-based and agglutination methods) and developed FTIR assay; eventually, the
sensitivity and specifcity of the developed method were calculated. In summary, four distinct FTIR
spectra associated with four species of Shigella were obtained with wide variations in three defnite
regions, including 1800–1550 cm−1, 1550–1100 cm−1, and 1100–800 cm−1 distinguish these species
from each other. In this study, we found the FTIR method followed by PCA analysis with specifcity,
sensitivity, diferentiation error and correct diferentiation rate values of 100, 100, 0 and 100%,
respectively, for identifcation and diferentiation of all species of the Shigella in stool samples
