Multi-laboratory evaluation of the rapid genoserotyping array (SGSA) for the identification of Salmonella serovars

Abstract

Salmonella serotyping is an essential first step for identification of isolates associated with disease outbreaks. The Salmonella genoserotyping array (SGSA) is a microarray-based alternative to standard serotyping designed to rapidly identify 57 of the most commonly reported serovars through detection of the genes encoding surface O and H antigens and reporting the corresponding serovar in accordance with the existing White-Kaufmann-Le Minor serotyping scheme. In this study, we evaluated the SGSA at 4 laboratories in 3 countries by testing 1874 isolates from human and non-human sources. The SGSA correctly identified 96.7% of isolates from the target 57 serovars. For the prevalent and clinically important Salmonella serovars Enteritidis and Typhimurium, test specificity and sensitivity were greater than 98% and 99%, respectively. Due to its high-throughput nature, the SGSA is a rapid and cost-effective alternative to standard serotyping for identifying the most prevalent serovars of Salmonella.

Keywords: Evaluation; H-antigen; Microarray; O-antigen; Salmonella; Serotyping.