Effects of different pretreatment methods on microbial yield from infected tissues

Abstract

Background: This study aimed to evaluate the effects of different pretreatment methods on the microbial yield in infected tissues. Methods: Strains of Staphylococcus aureus (SA), Escherichia coli (EC) and Candida albicans (CA) were used to construct single-surface, full-surface, and internal infection models in sterile pork tissue. Manual milling (MM), mechanical homogenization (MH), sonificated (SF), dithiothreitol (DTT), and direct culture (DC) were used to pretreat tissues, the microbial yield from different pretreatment methods were compared. At the same time, periprosthetic tissues collected intraoperatively from periprosthetic joint infection (PJI) patients were pretreated with the same methods. Results: The study showed that the microbial yield from MH pretreatment was significantly higher than that of MM (P <0.01) and SF pretreatment method (P <0.01). Furthermore, in the internal infection model, the microbial yield from MH group was also significantly higher than that of SF (P <0.01), DTT (P <0.01), and DC group (P <0.01). Moreover, the number of bacterial colonies obtained from periprosthetic tissues pretreated by MH was significantly higher than pretreated by other pretreatment methods (P = 0.004). Conclusions: The effects of MH and DTT in microbial yield were significantly higher than that of DC, SF and MM, and these methods can be used to process multiple tissue samples at the same time, which might further improve the sensitivity of infectious disease.