Relationship between biofilm-forming microorganisms (BFM:  Staphylococcus aureus and Pseudomonas aeruginosa) and DEFB1 gene variants on β-defensin levels in periprosthetic joint infection (PJI)

Background The purpose of this study was to investigate the relationship between biofilm-forming microorganisms (BFM) and DEFB1 gene variants on β-defensin levels in patients with periprosthetic joint infection (PJI) of Mexican origin. Methods and results One hundred and five clinical aspirates were obtained from patients with suspected PJI. After microbiologic culture, samples were classified as non-septic and septic; of the latter, only those positive for Staphylococcus aureus and Pseudomonas aeruginosa were selected. β-Defensin levels were quantified by ELISA, DNA was extracted from total leukocytes of the samples, and − 20G > A (rs11362) and − 44 C > G (rs1800972) variants were genotyped using TaqMan probes. Forty-one clinical aspirates were non-septic, 18 were positive for S. aureus and 18 were positive for P. aeruginosa . It was observed that β-defensin levels were higher in the P. aeruginosa group compared to S. aureus group (2339.0 pg/mL IQR = 1809.2 vs. 1821.3 pg/mL IQR = 1536.4) and non-septic group (2339.0 pg/mL IQR = 1809.2 vs. 1099.7 pg/mL IQR = 1744.5, P