Comparing the ability of luminex xMAP(®) salmonella serotyping assay and traditional serotyping method for serotyping salmonella isolated from southern Chinese population

Aims: To investigate whether the Luminex xMAP(®) Salmonella Serotyping Assay (xMAP SSA) is applicable to serotype Salmonella from humans in southern China.

Methods and results: Two hundred and five Salmonella isolates from diarrhoea patients were serotyped by xMAP SSA in parallel with the traditional serotyping. Forty serotypes were identified among 205 isolates; the most prevalent serotypes identified were Salmonella Enteritidis, Salmonella Stanley, Salmonella I 4,5,12:i:-, and Salmonella Typhimurium. One hundred and ninety-five (95·1%, 195/205) isolates were serotyped completely by xMAP SSA, while 10 stereotypes were partially detected as they were not included in the assay. The xMAP SSA correctly identified 192 (98·5%, 192/195) isolates. Five nonmotile and three monophasic strains, which possessed flagellar antigen genes that weren't expressed, were completely serotyped by xMAP SSA; however, these isolates were left undetected by the traditional method.

Conclusion: The xMAP SSA used in the study is a microsphere-based, molecular assay that could rapidly and accurately serotype Salmonella. It is suitable to identify the serovars of Salmonella in southern China.

Significance and impact of the study: The xMAP SSA, with high-throughput characteristics, provides an accurate and rapid serotyping system that dramatically strengthens the capability of clinical and public health laboratories for Salmonella serotyping.