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Mycobacterium wolinskyi: A Rare Strain Isolated in a Persistent Prosthetic Knee Joint Infection

A Case Report

Bhatnagar, Nishit MS Ortho, DNB Ortho, MRCS1; Poojary, Aruna MD, DNB, D (ABMM), Dip HIC, CIC2; Maniar, Adit MBBS, MS Ortho3; Contractor, Armaity MD4; Rohra, Seema MD5; Kumar, Gaurav MS Ortho, Mch Ortho6

doi: 10.2106/JBJS.CC.18.00315
Case Reports

Case: A patient who underwent first-stage revision procedure elsewhere for prosthetic joint infection (PJI) of the knee with Kocuria rosea presented to us 9 months after the index surgery, with persistent infection. First-stage revision surgery was repeated and Mycobacterium wolinskyi, a rare rapidly growing nontuberculous mycobacterium (RGM), was isolated from samples obtained by sonication of the cement spacer. After a prolonged antibiotic course, definitive implantation surgery was done. One-year postimplantation, patient remains infection free.

Conclusions: This is only the second known case of knee PJI caused by M. wolinskyi. This case highlights the possibility of RGM getting masked by other organisms.

1Department of Orthopaedics, Indraprastha Apollo Hospital, New Delhi, India

2Department of Pathology and Microbiology, Breach Candy Hospital, Mumbai, India

3Lilavati Hospital & Research Centre and Breach Candy Hospital, Mumbai, India

4Breach Candy Hospital, Mumbai, India

5Department of Pathology and Microbiology, Breach Candy Hospital, Mumbai, India

6Jhansi Orthopaedic Hospital, Jhansi, India

E-mail address for N. Bhatnagar:

Investigation performed at the Department of Orthopaedics, Breach Candy Hospital, Mumbai, India

Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (

Most prosthetic joint infections (PJIs) are caused by Staphylococcus aureus and Gram-negative bacilli1. Routine microbiology culture methods fail to isolate a causative organism (culture-negative) in about 7% to 10% of PJIs2,3. One of the reasons for such false negative cultures are infections by mycobacteria, which are difficult to isolate and detect4. Rapidly growing nontuberculous mycobacteria (RGM), a small subset of mycobacteria, are emerging as an important cause of PJIs5. Here, we describe only the second known case of PJI of the knee caused by Mycobacterium wolinskyi, an RGM, which was masked by the presence of Kocuria rosea.

The patient was informed that data concerning the case would be submitted for publication, and he provided consent.

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Case Report

A 62-year-old man underwent bilateral sequential total knee arthroplasty for osteoarthritis in December 2015 at a high volume arthroplasty center in India. After an uneventful immediate postoperative period, he developed pain and swelling in the left knee approximately 6 weeks after the surgery. Despite 2 weeks of rest and nonsteroidal anti-inflammatory drugs, erythrocyte sedimentation rate (ESR) was 84 mm/hr (normal: 0-10 mm/hr) and C-reactive proteins (CRPs) were 68.2 mg/L (normal: 0-10 mg/L). Around 15 mL of thick, translucent fluid was aspirated from the knee and sent for analysis. Although no organism could be isolated from the fluid, a diagnosis of PJI was made based on the minor preoperative criteria as per the International Consensus Meeting definition for acute PJI (elevated ESR, elevated CRP, elevated synovial white blood cell counts, and elevated synovial polymorphonuclear neutrophils percentage)6.

A month after the aspiration, the patient underwent first-stage revision surgery (debridement, implant removal, lavage, and articulated cement spacer implantation) at the primary treating center. K. rosea, a Gram-positive coccus, was isolated from tissue samples obtained during this surgery, thus confirming the diagnosis of PJI. As per the antibiotic sensitivity profile, intravenous piperacillin-tazobactam and clindamycin were given for 6 weeks and then switched to oral clindamycin for another 6 weeks.

The patient presented to us for the first time, 6 months after the first-stage revision surgery with pain, 5° to 20° knee range of motion (ROM) and inability to ambulate beyond 100 m. The distal end of the scar overlying the tibial tuberosity had a tender, indurated swelling (Fig. 1-A). CRP was 22 mg/L (normal 0-10 mg/L) and ESR was 41 mm/hr (normal 0-10 mm in first hour). Aspiration of the knee provided around 5 mL of thick serosanguinous fluid, which was sterile on culture.

Fig. 1

Fig. 1

Based on the clinical suspicion that the infection had not subsided, the patient was taken up for repeat first-stage revision surgery (spacer removal, debridement, lavage, and new articulated cement spacer implantation). Intraoperatively, the distal end of the scar overlying the tibial tuberosity was found to be communicating with a cavity in the tibial condyle and was hence excised (Figs. 1-B and 1-C).

During this surgery, the following specimens were sent for culture: synovial tissue, tibial tissue, femur tissue, tissue from tibial medullary canal, and cement spacer. All tissue samples were processed aseptically and kept for incubation for 7 days at 35°C. The cement spacer was subjected to sonication and the sonicated fluid was subcultured on 5% sheep blood agar, MacConkey agar, and chocolate agar, which was incubated for 7 days at 35°C in ambient air and capnophilic environment respectively. This fluid was also inoculated into blood culture bottles (aerobic, anaerobic, and Myco/F Lytic—BD India). All tissue samples remained culture negative after 7 days. The Myco/F Lytic bottle flashed positive on the fourth day of incubation and showed slender Gram-positive bacilli, which were also acid fast with Ziehl–Neelsen stain (20%). The growth was subsequently identified as M. wolinskyi, a rapidly growing nontuberculous mycobacteria, using the polymerase chain reaction sequencing method. Drug susceptibility was performed using the broth microdilution method as recommended by the Clinical Laboratory Standards Institute M24-A2, 20117.

The isolate was found to be susceptible to the following antimicrobial agents (minimum inhibitory concentration in parenthesis): Linezolid (2 mg/dL), Amikacin (8 mg/dL), Ciprofloxacin (1 mg/dL), and Moxifloxacin (<0.25 mg/dL). As per sensitivity, antibiotics were started (Fig. 2). Postoperative period was uneventful, and 6 weeks after the repeat first-stage revision surgery, the patient was able to ambulate without support.

Fig. 2

Fig. 2

After an antibiotic free period of 6 weeks, the knee was aspirated. Microbiological analysis of the synovial fluid, with specific focus on mycobacteria, did not detect any organism. Inflammatory biomarkers (ESR—5 mm/hr and CRP—4.2 mg/L) were also within normal limits.

The definitive reimplantation surgery (extensile exposure by quadriceps snip, cement spacer extraction, and constrained prosthesis implantation) was performed 6 months after the repeat first-stage procedure (Fig. 3). Postoperative period was uneventful. Intraoperative cultures were followed for up to 6 weeks and turned out to be sterile.

Fig. 3

Fig. 3

At 1-year follow-up, the patient was pain free and walking with a normal gait. Knee ROM was up to 130° and there was no extensor lag. The surgical site was quiet and inflammatory parameters were within normal limits (ESR—14 mm/hr, CRP—2.6 mg/L).

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Mycobacterium tuberculosis, although rare, is well known to cause PJI8. Nontuberculous mycobacteria are rare causative agents of PJIs and may be classified as rapidly growing or slow growing mycobacteria. RGMs have recently gained clinical significance as they are increasingly being recognized as causative agents for early onset PJIs9-11.

RGMs comprise 3 clinically relevant groups, Mycobacterium fortuitum group, Mycobacterium abscessus group, and Mycobacterium smegmatis group. Brown et al12. first described M. wolinskyi as a part of the M. smegmatis group in 1999. At the time of discovery of this species, only 3 cases of osteoarticular infections were attributed to M. wolinskyi. One of them was an osteomyelitis of the sternum after cardiac surgery, another was osteomyelitis of the foot after injury by stepping onto a nail, and the third was an osteomyelitis around the elbow after an open fracture12.

M. wolinskyi, like other RGMs, are environmental bacteria with the potential to contaminate water. Faulty and inappropriate sterilization practices have been implicated as the cause of surgical site infections (SSIs) caused by RGMs13. Piped water systems and common decontaminants such as glutaraldehydes are also a source of RGMs14,15. The primary surgery of this patient was done at a high volume arthroplasty center with frequent instrument sterilization cycles. We hypothesize this as the risk factor leading to M. wolinskyi infection. An extensive literature search revealed only 2 reported cases of PJI caused by M. wolinskyi. Pulcini et al16. and Lee et al17. in their separate reports have described a case of PJI, in the hip and knee, respectively, in which M. wolinskyi has been proven to be the causative organism (Table I). However, the portal of entry for the organism could not be detected in either of the PJIs caused by M. wolinskyi.

TABLE I - Summary of reports of prosthetic joint infections caused Mycobacterium wolinskyi
Author Year Age, Sex Primary Surgery Time to Symptoms, Time to Identify Organism Surgical Treatment Antibiotic Treatment Follow-up
Lee,17 2013 65, F Total knee arthroplasty 3 weeks, 6 weeks Debridement and liner exchange Empirical No recurrence at 2 years
 Vancomycin Osteolysis in posterior femoral condyle and radiolucent line at the bone–cement interface under the tibial component
For mycobacteria
After sensitivity
 Doxycycline for 4 months
Pulcini,16 2006 83, F Total hip arthroplasty 4 months, 11 months First stage 1 month No recurrence at 1-year follow-up
 Debridement  Moxifloxacin
 Acetabular component removal  Minocycline
 Spacer implantation  Amikacin
Second stage 6 months
 Spacer removal  Moxifloxacin Minocycline
 Revision THA
Bhatnagar et al, (This report) 2019 62, M Total knee arthroplasty 6 weeks, 11 months First stage 6 weeks Infection free at 1-year follow-up. Excellent knee function.
 Debridement  Amikacin
 Implant removal  Linezolid
 Spacer implantation  Moxifloxacin
Repeat first stage 3 months
 Debridement  Moxifloxacin
 Spacer change  Linezolid
Second stage
 Spacer removal
 Revision TKA

Management of SSI due to RGMs includes antibiotic treatment along with surgical debridement16,17. There are no standardized treatment regimens for RGMs; hence, antibiotic therapy is based on the in-vitro drug susceptibility data18. It is essential to grow and speciate RGMs as most of them show unique intrinsic resistance patterns to some antimicrobial agents. Although the remaining RGMs are susceptible to clarithromycin, the M. smegmatis group along with M. wolinskyi is resistant to clarithromycin5,12. Hence reports of PJI caused by M. wolinskyi have used non-clarithromycin–based therapy, including an aminoglycoside for 4 weeks followed by 2 or 3 drug regimens comprising of quinolones and tetracyclines, for a period of 4 to 6 months (Table I)16,17. We also used in-vitro drug susceptibility data to guide our choice of antibiotics. Unlike the other reports of PJI caused by M. wolinskyi, our strain was susceptible to Linezolid and resistant to the tetracyclines.

K. rosea is a Gram-positive coccus, closely related to the genus Micrococcus and are commensals of the oropharynx and skin19. There are no reported cases of K. rosea causing PJI. There is only a single report of co-infection of K. rosea and rapidly growing nontuberculous mycobacteria (M. abscessus), causing endocarditis in an intravenous drug user20.

Ours is only the second known case of knee PJI caused by M. wolinskyi. Infection with M. wolinskyi persisted even after eradication of K. rosea and was successfully treated by a two-stage revision arthroplasty. We hypothesize that the knee was infected by both the organisms during the primary surgery. At the primary treating center, the NTM may have been missed because they usually grow after 72 hours and would require further incubation of the agar plates while K. rosea would grow within 48 hours. This highlights the need to follow cultures despite having identified an organism. This case also highlights the need to be aware of the possibility of coinfection of RGMs and with other organisms.

Note: The authors thank Dr. Rajesh N. Maniar for his guidance in the preparation of this case report and for granting us the permission to use clinical data of his patient.

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1. Peel TN, Cheng AC, Buising KL, Choong PF. Microbiological aetiology, epidemiology, and clinical profile of prosthetic joint infections: are current antibiotic prophylaxis guidelines effective? Antimicrob Agents Chemother. 2012;56(5):2386-91.
2. Berbari EF, Marculescu C, Sia I, Lahr BD, Hanssen AD, Steckelberg JM, Gullerud R, Osmon DR. Culture-negative prosthetic joint infection. Clin Infect Dis. 2007;45(9):1113-9.
3. Malekzadeh D, Osmon DR, Lahr BD, Hanssen AD, Berbari EF. Prior use of antimicrobial therapy is a risk factor for culturenegative prosthetic joint infection. Clin Orthop Relat Res. 2010;468:2039-45.
4. Yoon HK, Cho SH, Lee DY, Kang BH, Lee SH, Moon DG, Kim DH, Nam DC, Hwang SC. A review of the literature on culture-negative periprosthetic joint infection:epidemiology, diagnosis and treatment. Knee Surg Relat Res. 2017;29(3):155-64.
5. Yang SC, Hsueh PR, Lai HC, Teng LJ, Huang LM, Chen JM, Wang SK, Shie DC, Ho SW, Luh KT. High prevalence of antimicrobial resistance in rapidly growing mycobacteria in Taiwan. Antimicrob Agents Chemother. 2003;47(6):1958-62.
6. Goswami K, Parvizi J, Maxwell Courtney P. Current recommendations for the diagnosis of acute and chronic PJI for hip and knee-cell counts, alpha-defensin, leukocyte esterase, next-generation sequencing. Curr Rev Musculoskelet Med. 2018;11(3):428-8.
7. CLSI. Susceptibility Testing of Mycobacteria, Nocardiae, and Other Aerobic Actinomycetes; Approved Standard—Second Edition. CLSI Document M24-A2. Wayne, PA: Clinical and Laboratory Standards Institute; 2011.
8. Marculescu CE, Berbari EF, Cockerill FR III, Osmon DR. Fungi, mycobacteria,zoonotic and other organisms in prosthetic joint infection. Clin Orthop Relat Res. 2006;451:64-72.
9. Eid AJ, Berbari EF, Sia IG, Wengenack NL, Osmon DR, Razonable RR. Prosthetic joint infection due to rapidly growing mycobacteria: report of 8 cases and review of the literature. Clin Infect Dis. 2007;45:687-94.
10. Amit P, Rastogi S, Marya S. Prosthetic knee joint infection due to Mycobacterium abscessus. Indian J Orthop. 2017;51(3):337-42.
11. Jitmuang A, Yuenyongviwat V, Charoencholvanich K, Chayakulkeeree M. Rapidly-growing mycobacterial infection: a recognized cause of early-onset prosthetic joint infection. BMC Infect Dis. 2017;17(1):802.
12. Brown BA, Springer B, Steingrube VA, Wilson RW, Pfyffer GE, Garcia MJ, Menendez MC, Rodriguez-Salgado B, Jost KC Jr, Chiu SH, Onyi GO, Bottger EC, Wallace RJ Jr. Mycobacterium wolinskyi sp. nov. and Mycobacterium goodii sp. nov., two new rapidly growing species related to Mycobacterium smegmatis and associated with human wound infections: a cooperative study from the International Working Group on Mycobacterial Taxonomy. Int J Syst Bacteriol. 1999;49(4):1493-511.
13. Kannaiyan K, Ragunathan L, Sakthivel S, Sasidar AR, Muralidaran, Venkatachalam GK. Surgical site infections due to rapidly growing mycobacteria in puducherry, India. J Clin Diagn Res. 2015;9(3):DC05-8.
14. Selvaraju SB, Khan IU, Yadav JS. Biocidal activity of formaldehyde and nonformaldehyde biocides toward Mycobacterium immunogenum and Pseudomonas fluorescens in pure and mixed suspensions in synthetic metal working fluid and saline. Appl Environ Microbiol. 2005;71(1):542-6.
15. Phillips MS, von Reyn CF. Nosocomial infections due to nontuberculous mycobacteria. Clin Infect Dis. 2001;33(8):1363-74.
16. Pulcini C, Vandenbussche E, Podglajen I, Sougakoff W, Truffot-Pernot C, Buu-Hoï A, Varon E, Mainardi JL. Hip prosthesis infection due to Mycobacterium wolinskyi. J Clin Microbiol. 2006;44(9):3463-4.
17. Lee YS, Nam SW, Park YS, Lee BK. Mycobacterium wolinskyi infection after total knee arthroplasty in a healthy woman. J Orthop Sci. 2015;20(1):229-31.
18. Ariza-Heredia EJ, Dababneh AS, Wilhelm MP, Wengenack NL, Razonable RR, Wilson JW. Mycobacterium wolinskyi: a case series and review of the literature. Diagn Microbiol Infect Dis. 2011;71(4):421-7.
19. Stackebrandt E, Koch C, Gvozdiak O, Schumann P. Taxonomic dissection of the genus Micrococcus: Kocuria gen. nov., Nesterenkonia gen. nov., Kytococcus gen. nov., Dermacoccus gen. nov., and Micrococcus Cohn 1872 gen. emend. Int J Syst Bacteriol. 1995;45(4):682-92.
20. Garcia DC, Nascimento R, Soto V, Mendoza CE. A rare native mitral valve endocarditis successfully treated after surgical correction. BMJ Case Rep. 2014:2014.

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