A 7-member SNP Assay on the iPlex MassARRAY Platform Provides a Rapid and Affordable Alternative to Typing Major AfricanStaphylococcus aureusTypes

Abstract

AbstractBackgroundData on the clonal distribution ofStaphylococcus aureusin Africa is scanty, partly due to high costs and long turnaround times imposed by conventional genotyping methods such asspaand multilocus sequence typing (MLST) warranting the need for alternative typing approaches. This study applied and evaluated the accuracy, cost and time of using iPlex massARRAY genotyping method on Kenyan staphylococcal isolates.MethodsFifty four clinicalS. aureusisolates from three counties were characterized using iPlex massARRAY,spaand MLST typing methods. Ten Single Nucleotide Polymorphisms (SNPs) from theS. aureusMLST database were assessed by iPlex massARRAY.ResultsThe iPlex massARRAY assay grouped the isolates into 14 SNP genotypes with 9/10 SNPs interrogated showing high detection rates (average 89%). spaand MLST typing revealed 22spatypes and 21 STs that displayed unique regional distribution.spatype t355 (ST152) was the dominant type and t2029 and t037 (ST 241) were observed among MRSA strains. MassARRAY showed 83% and 82% accuracy againstspaand MLST typing respectively in isolate classification. Moreover, massARRAY identified all MRSA strains and a novelspatype. MassARRAY had reduced turnaround time (<12 hrs) compared tospa(3 days) and MLST (20 days) typing. The iPlex massARRAY cost approximately 18 USD compared tospa(30 USD) and MLST (126 USD) typing based on consumable costs/isolate.ConclusionUpon validation with a larger collection of isolates, iPlex massARRAY could provide a faster, more affordable and fairly accurate method of resolving AfricanS.aureusisolates especially in large surveillance studies.