High efficacy of molecular methods for identification of Salmonella enterica serogroups: A 2-year surveillance

Introduction: Salmonella is one of the most important causes of diarrhea in developing countries including Iran. The genus Salmonella is consisted of different serovars, a few of which are responsible for most salmonella infections. Because cross reaction commonly occurs among serogroups, this study was determined to define the serogroup specification of Salmonella species isolated during a 2-year period through serological and molecular methods. Methodology: A total of 6100 patients with acute diarrhea from Tehran provinces in Iran were included in this study and 78 Salmonella enterica were obtained from patients (1.28). All isolates were confirmed by specific primers. The serogrouping of isolates was done using monospecific antisera. Serogroup specifications of isolates were confirmed by polymerase chain reaction method using primers specific for each serogroup. Results: All of the isolates produced positive results in invA amplification. The results showed the dominance of serogroups D (34.6) and E (28.2) among the isolates, which were confirmed by polymerase chain reaction specific for each serogroup. The least prevalent were members of serogroup A (n = 2, 2.6), whereas serogroups C and B constituted 24.4 (n = 19) and 10.2 (n = 8) of isolates, respectively. Discussion: Conversion of agglutination assays to amplification assays takes some advantages including increased sensitivity and no fear of cross reaction. The probability of designing more specific primers in the future gives new insight to increasing the accuracy and specificity of molecular methods, which consequently leads to identification of more serotypes and serogroups and increases their efficacy. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.