Validation of a direct-to-PCR COVID-19 detection protocol utilizing mechanical homogenization: A model for reducing resources needed for accurate testing

Efficient and effective viral detection methodologies are a critical piece in the global response to COVID-19, with PCR-based nasopharyngeal and oropharyngeal swab testing serving as the current gold standard. With over 100 million confirmed cases globally, the supply chains supporting these PCR testing efforts are under a tremendous amount of stress, driving the need for innovative and accurate diagnostic solutions. Herein, the utility of a direct-to-PCR method of SARS-CoV-2 detection grounded in mechanical homogenization is examined for reducing resources needed for testing while maintaining a comparable sensitivity to the current gold standard workflow of nasopharyngeal and oropharyngeal swab testing. In a head-to-head comparison of 30 patient samples, this initial clinical validation study of the proposed homogenization-based workflow demonstrated significant agreeability with the current extraction-based method utilized while cutting the total resources needed in half.

The Utility of Mechanical Homogenization in COVID-19 Diagnostic Workflows

The use of mechanical homogenization in patient sample preparation for COVID-19 diagnostics has proven impactful in the face of the global pandemic caused by SARS-CoV-2. Through methods including bead beating and shaker mill homogenization novel approaches to viral detection have been developed and improvements have been made to existing diagnostic workflows for the improvement of throughput and automation capacity. The application of mechanical homogenization techniques has enhanced the sensitivity and methodology for many molecular based approaches to COVID-19 detection and from a variety of sample types ranging from saliva to nasopharyngeal swabs. Additionally, this technology has been used to help increase laboratory safety during sample processing through efficient viral lysis. Herein, the many benefits of mechanical homogenization for COVID-19 detection will be discussed in the context of the many diagnostic workflows currently utilizing the technique.

Microbial yield from infectious tissues pretreated by various methods: an invitro study

Background This study aimed to evaluate the effects of different pretreatment methods on the microbial yield from infectious 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 these tissues, the microbial yield from different pretreatment methods were recorded and compared. Moreover, periprosthetic tissues collected intraoperatively from periprosthetic joint infection (PJI) patients were used as a verification. 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 diagnostic sensitivity of infectious disease.

Effects of different pretreatment methods on microbial yield from infected tissues

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.

Effects of different pretreatment methods on microbial recovery of infected tissues

This study aimed to evaluate the effects of different pretreatment methods on the degree of microbial recovery in infected tissues. Standard 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), ultrasonic lysis (UL), dithiothreitol (DTT), and direct culture (DC) were used to pretreat infection tissues, the ability of the different pretreatment methods to achieve pathogen recovery in the different bacterial infection models was compared. At the same time, periprosthetic tissues collected from periprosthetic joint infection (PJI) were pretreated with the same methods. We showed that regardless of whether the single-surface or full-surface infection model was used in SA, EC, and CA infection, the microbial acquisition in the MH group was significantly higher than that in the MM (P <0.01) and UL groups (P <0.01). In the internal infection model, the microbial acquisition of the MH group was significantly higher than that of the MM (P <0.01), UL (P <0.01), DTT (P <0.01), and DC groups (P <0.01). In the PJI cases, the number of bacterial colonies obtained by MH was significantly higher than that obtained by other pretreatment methods (P = 0.004). The effects of MH and DTT in microbial recovery were significantly better than that of DC, UL and MM, and these methods can be used to process multiple tissue samples at the same time, which can further improve the efficiency of clinical microbial diagnosis.