No associations established between single nucleotide polymorphisms in human Toll-like receptor 2 and Toll-interacting protein and Staphylococcus aureus bloodstream infections

Abstract

Staphylococcus aureus bloodstream infections (SABSI) are associated with high morbidity and mortality. The Toll‐like receptor 2 (TLR2) and Toll‐interacting protein (TOLLIP) are important in recognition and regulation of human innate immunity response to S. aureus. Single nucleotide polymorphisms (SNPs) in the TLR2 and TOLLIP encoding genes have been associated with disease, including BSI. The aim of this study was to examine potential associations between a selection of SNPs in the genes encoding TLR2 and TOLLIP, and predisposition, severity, and outcome of SABSI. All patients ≥18 years of age with at least one S. aureus positive blood culture collected from March 2011 through February 2014 at Akershus University Hospital, Lørenskog, Norway, were considered for inclusion. Patients attending elective orthopaedic surgery (total hip and knee replacements, lumbar surgery) served as a control group. The TLR2 Arg753Gln, TLR2 Pro631His, TOLLIP rs5743942, and rs5743867 polymorphisms were analysed using TaqMan SNP Genotyping Assays. A total of 209 SABSI patients and 295 controls were included. The TLR2 Arg753Gln and TLR2 Pro631His polymorphisms were infrequent with no homozygotes and <10% heterozygotes. The included TLR2 and TOLLIP polymorphisms were not associated with susceptibility to SABSI, severity, 30‐day all‐cause mortality, or SABSI caused by the clonal complex 30 (CC30) genotype.