Diagnostic Role of Metagenomic Next-Generation Sequencing in Tubercular Orthopedic Implant-Associated Infection

Figures & data

Table 1 Demographic Information of the 10 Patients with Tuberculous Orthopedic Implant Infections

Patient ID	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10
Type	PJI	PJI	PJI	PJI	PJI	PJI	PJI	PJI	FRI	FRI
Sex/Age	F/64	M/69	M/54	M/58	M/59	M/45	F/36	M/85	M/68	M/55
Underlying disease	Arrhythmias	None	None	DM	HT	None	None	None	HT	HT
History of Tuberculosis	No	Hip joint TB	No	No	No	No	No	PTB	No	No
Primary diagnosis	OA	OA	OA	OA	OA	OA	TFHN	OA	Tibia fracture	Tibia and fibula fracture
Primary surgery	TKA	AFHR	UKA	THA	TKA	TKA	THA	TKA	ORIF	ORIF
Time to infection after surgery	7 y	11 y	2 y	8 m	5 m	2 y	1 y	2 y	20y	1y
Duration of Symptoms	6w	10d	3m	4m	14d	10w	8w	3m	5m	20d
Clinical manifestation	Pain, pus	Pain, pus	Pain, pus	Pain	Pain	Pain, swelling	Pain, swelling, pus	Pain, swelling	Pain, swelling, pus	Pain
ESR (mm/h)	76	12	75	34	35	120	39	42	39	20
CRP (mg/L)	13.3	2.31	29.6	29.71	39.7	81.2	0.5	21.4	7.09	15.93
SF-WBC (× 10^6/L)	32,580	36,145	2400	7471	8034	38,400	/	30,040	/	/
PMN (%)	87	60	82	92	96	90	/	92	/	/
Triple-Phase Bone Scanning	Positive	Negative	Positive	/	/	Positive	Positive	/	/	Positive (PET-CT)

Abbreviations: PJI, prosthetic joint infection; FRI, fracture-related infection; F, female; M, male; DM, diabetes; HT, hypertension; TB, tuberculosis; PTB, pulmonary tuberculosis; OA, osteoarthritis; TFHN, traumatic femoral head necrosis; TKA, total knee arthroplasty; AFHR, artificial femoral head replacement; UKA, unicompartmental knee arthroplasty; THA, total hip arthroplasty; ORIF, open reduction and internal fixation; y, year; m, month; SF, synovial fluid; WBC, white blood cell; PMN, polymorphonuclear leukocyte.

Table 2 Laboratory Tests, Microbial Culture, and Histopathological Examination Results of 10 Patients

Patient ID	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10
Laboratory tests
TB-Ab	Negative	Negative	Negative	Negative	Negative	Negative	IgG (+)	/	Negative	Negative
QPCR	Negative	Positive	Negative	Negative	Positive	Negative	Negative	/	Negative	Negative
T-SPOT.TB	Negative	Negative	/	Negative	Negative	Negative	Positive	/	Positive	Negative
PPD	Negative	++	/	Negative	Negative	++++	+++	/	+	Negative
Microbial culture
PF	Negative	Negative	Negative	Negative	Negative	S. aureus	Negative	Negative	Negative	Negative
PSF	Negative	Negative	Acid-fast bacteria	Negative	Negative	S. aureus	Negative	Negative	/	/
PT	Negative	Acid-fast bacteria	Acid-fast bacteria	Negative	Acid-fast bacteria	Negative	Acid-fast bacteria	Acid-fast bacteria	Negative	Negative
Histopathological examination
Intraoperative observation	Chronic inflammation	Chronic granulomatous inflammation	Chronic granulomatous inflammation	Chronic granulomatous inflammation	Chronic granulomatous inflammation	Chronic inflammation	Chronic inflammation	Chronic inflammation	Chronic granulomatous inflammation	Chronic granulomatous inflammation
Ziehl–Neelsen stain	Negative	Negative	Positive	Negative	Negative	Negative	Positive	Negative	Negative	Negative

Abbreviations: TB, tuberculosis; Ab, antibody; QPCR, quantitative Real-time PCR; PF, purulent fluid; PSF, prosthetic sonicate fluid; PT, Periprosthetic tissue;S.aureus, Staphylococcus aureus.

Table 3 Metagenomic Next-Generation Sequencing Results of 10 Patients

Patient ID	Metagenomic Results
	Sample	Species	Reads
P1	PSF	Afipia birgiae	159
		Mycobacterium gordonae	13
		MTBC	1
P2	PT	MTBC	32
P3	PF	MTBC	15
P4	PT	MTBC	3
P5	PT	MTBC	7
P6	PSF	S. aureus	2027
		Prevotella melaninogenica	6
		MTBC	27
P7	PSF	MTBC	32
P8	PSF	MTBC	99
P9	PT	MTBC	23
P10	PT	MTBC	169

Abbreviations: MTBC, Mycobacterium tuberculosis complex; PF, purulent fluid; PSF, prosthetic sonicate fluid; PT, Periprosthetic tissue; S. aureus, Staphylococcus aureus.

Figure 1 The performance of laboratory tests, culture, mNGS and histopathology for preoperative and intraoperative diagnosis of MTBC. Time and results of pathogen detection using laboratory tests, culture, mNGS and histopathological examination of each individual patient are respectively presented.

Figure 2 The standardized diagnosis procedure for TB-IAI.