Arthritis Due toMycobacterium xenopi:A Retrospective Study of 7 Cases in France

Pleuritis due to Mycobacterium xenopi without pulmonary infection

Nontuberculous mycobacteria (NTM) may cause pulmonary and extra-pulmonary disease in both immunocompetent and immunocompromised patients. Pleuritis is an uncommon manifestation on NTM disease, and pleuritis caused by Mycobacterium xenopi has only been described once before. Because it is considered to be an environmental contaminant, isolation of M. xenopi from bronchopulmonary secretions or other sites is often dismissed. The disease caused by M. xenopi is usually a pulmonary infection and typically occurs in severely immunocompromised individuals or in immunocompetent patients with an underlying chronic lung disease. We describe an unusual case of pleuritis caused by M. xenopi in a patient without an underlying chronic lung disease and with no evidence of a concurrent M. xenopi pulmonary infection.

Prosthetic joint infection due to Mycobacterium xenopi: a review of the literature with a new case report

PURPOSE

Extrapulmonary infections due to M. xenopi, particularly osteoarticular localizations, are rare. The purpose of this paper is to describe a case of prosthetic hip infection and to review the published literature on cases of M. xenopi osteoarticular infections.

METHODS

Literature search was performed in the following databases: MEDLINE (PubMed), Embase, Central (the Cochrane Library 2019, Issue 1), LILACS (BIREME) (Latin American and Caribbean Health Science Information database) and Clinical Trials databases (14th August 2018). We included all case reports and case series on adult patients diagnosed with bone or joint infection by M. xenopi for whom the treatment and outcome were specified.

RESULTS

We retrieved 30 cases published between 1982 and 2012, among which 25 (83.3%) were reported from Europe. The two most common infection sites were spine (12/30, 40%) and knee (9/30, 30%). Risk factors for infection were previous invasive procedures (11/30, 36.7%), autoimmune disease (8/30, 26.7%), AIDS (4/30, 13.3%) and other comorbidities (2/30, 6.7%); five patients had no past medical history. All patients were treated with antibiotic combinations, but composition and duration of regimens hugely varied. Surgical intervention was performed in 16 patients (53.3%). Only 11 patients obtained full recovery of articular mobility after treatment.

CONCLUSION

This work highlights the difficulties in diagnosing and treating M. xenopi osteoarticular infections. Globally, evidence supporting the best practice for diagnosis and treatment of this infection is scanty.

Other Slow-Growing Nontuberculous Mycobacteria

The list of clinically important slow-growing nontuberculous mycobacteria (NTM) continues to expand as new species are identified and older ones are found to be pathogenic. Based on pigment production, the strains may be classified as photochromogenic, scotochromogenic, or unpigmented. Some of these organisms are not newly discovered but have heretofore been considered virtually nonpathogenic. Previously, many were regarded as contaminants when isolated from clinical specimens. Ubiquitous in nature, many NTM have been isolated from groundwater or tap water, soil, house dust, domestic and wild animals, and birds. Most infections result from inhalation or direct inoculation from environmental sources. They are not spread from person to person. The infections may be localized or disseminated. In most cases, the optimal regimen or duration of therapy has not been firmly established. The results of in vitro susceptibility testing may be used to select a therapeutic regimen. Many experts recommend clarithromycin with companion drugs such as rifampin and ethambutol for most, but not all, slowly growing species. Aminoglycosides, clofazimine, fluoroquinolones, linezolid, pyrazinamide, or trimethoprim-sulfamethoxazole also may be effective against some strains. Immunocompetent patients with clinically significant infections with NTM usually should receive 18 to 24 months of therapy. Infected immunocompromised patients, particularly those with disseminated infection, probably should receive therapy as long as their immune systems remain impaired. Some of the species discussed include Mycobacterium alsiense, M. celatum, M. gordonae, M. haemophilum, M. kyorinense, M. malmoense, M. simiae complex, M. szulgai, M. terrae complex, M. ulcerans, and M. xenopi.

Arthroscopic synovectomy, irrigation, and debridement for treatment of septic ankle arthrosis: a systematic review and case series

Septic arthrosis of the ankle is a rare, often devastating, infection, with a high potential for morbidity and mortality. Delay in treatment can lead to cartilage erosion, painful synovitis, and osteomyelitis. Septic ankle arthrosis deserves prompt recognition and intervention. However, quality, sound, protocol-directed arthroscopic treatment of septic ankle arthrosis of the ankle has not yet been reported. We performed a systematic review of the electronic databases and other relevant peer-reviewed sources to determine the outcomes and treatment protocols associated with septic ankle arthrosis treated with arthroscopic synovectomy, irrigation, and debridement. Nine studies, involving a total of 15 ankles, met our inclusion criteria. In addition, we present the short-term outcomes of a protocol-driven arthroscopic synovial biopsy, deep culture procurement, synovectomy, irrigation, and debridement approach for 8 ankles (8 patients). To our knowledge, this would be the largest individual case series specific to arthroscopic treatment of septic ankle arthrosis. The most common infectious organism reported in the systematic review and in our case series was methicillin-sensitive Staphylococcus aureus. Arthroscopic synovectomy, irrigation, and debridement represents an acceptable treatment method for septic ankle arthrosis and demonstrated outcomes similar to the more traditional open approach, with fewer complications. Additional, appropriately weighted, randomized controlled studies with long-term follow-up are warranted.

Complete genome sequence of Mycobacterium xenopi type strain RIVM700367

Mycobacterium xenopi is a slow-growing, thermophilic, water-related Mycobacterium species. Like other nontuberculous mycobacteria, M. xenopi more commonly infects humans with altered immune function, such as chronic obstructive pulmonary disease patients. It is considered clinically relevant in a significant proportion of the patients from whom it is isolated. We report here the whole genome sequence of M. xenopi type strain RIVM700367.