[Application of metagenomic next-generation sequencing technology in pathogen detection of burn patients and acute or chronic wound patients].

Li, F; Yin, K N; Hu, Q; Zhang, Q X; Chen, Q; Yang, L L; Chen, X; Sun, Y J

Objective: To explore the value of using metagenomic next-generation sequencing (mNGS) to detect pathogens in burn patients and acute or chronic wound patients. Methods: A retrospective cohort study was conducted. From March 2019 to June 2020, 11 burn patients and acute or chronic wound patients (including 10 males and 1 female, aged 23 to 85 years) in the Fourth Medical Center of PLA General Hospital were conformed to the inclusion criteria. A total of 23 specimens were collected, including 6 whole blood specimens, 1 skin tissue specimen, 1 drained pus specimen, and 15 wound secretion swab specimens. Each specimen was divided into two parts, one for microbial culture identification and the other for mNGS detection. The number and types of pathogens detected by the microbial culture and mNGS were recorded, and the consistency of the two methods were compared. Data were statistically analyzed with paired Wilcoxon rank sum test. Results: With the microbial culture method, in all the 23 specimens, pathogens were not detected in 5 specimens, and 35 pathogens were detected in the remaining 18 specimens, belonging to 9 species of bacteria and 2 species of fungi. A single pathogen was detected in 5 specimens, 2 pathogens were detected in 9 specimens, and 3 pathogens were detected in 4 specimens. With the mNGS method, in all the 23 specimens, no pathogen was detected in 1 specimen, 75 pathogens were detected in the remaining 22 specimens, belonging to 28 species of bacteria, 3 species of fungi, and 3 species of viruses. A single pathogen was detected in 8 specimens, 2 pathogens were detected in 5 specimens, 3 pathogens were detected in 2 specimens, 4 pathogens were detected in 3 specimens, 6 pathogens were detected in 2 specimens, and 1 specimen each with 7 and 20 pathogens detected. The number of pathogens detected in each specimen by microbial culture method was 2(1, 2), which was significantly less than 2(1,4) by mNGS method (Z=3.359, P<0.01). In 5 specimens, no bacteria were detected by microbial culture method, while bacteria and virus were detected by mNGS method in each 2 specimens. Among the 14 specimens with two or more types of pathogens detected by mNGS method, the relative abundance of bacteria in the first place ranged from 28.8% to 95.9%. Of all the 23 specimens, 7 (30.4%) of the two methods had completely the same results, 5 (21.7%) of the results were completely inconsistent, and 11 (47.8%) of the results were not completely the same. Conclusions: Compared with the traditional microbial culture method, the mNGS method has higher detection sensitivity and stronger ability to detect pathogens, and can determine the main pathogens of mixed infections. As a supplement to the culture method, the mNGS method is expected to play an important role in the diagnosis of burn and acute or chronic wound infection.