Septic arthritis in the knee due to Mycobacterium xenopi in a patient undergoing hemodialysis

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.

A cluster of rapidly growing mycobacterial peritoneal dialysis catheter exit-site infections

In this case series, a cluster of 5 consecutive peritoneal dialysis patients with atypical mycobacterial exit-site infections in a single center within 20 months are described. Clinical features, treatment, and outcomes are discussed. Most patients had been treated with prolonged systemic antibiotic therapy for recurrent bacterial exit-site infections in the preceding months, and all had used topical gentamicin ointment for exit-site infection treatment or prophylaxis. It is postulated that this might have predisposed them to atypical mycobacterial exit-site infection as a result of selection pressure on uncommon organisms.

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

BACKGROUND

Mycobacterium xenopi is a nontuberculous mycobacterium responsible for opportunistic and nosocomial infections, chiefly of the lung; few cases of bone and joint infection have been reported. From July 1989 through May 1993, an outbreak of 58 cases of nosocomial discitis due to M. xenopi infection following percutaneous nucleotomy occurred in a French hospital. Peripheral M. xenopi arthritis seems exceedingly rare. We conducted a study to assess the epidemiological and clinical patterns of M. xenopi arthritis.

METHODS

We retrospectively reviewed cases of M. xenopi arthritis reported from May 1993 through October 2004.

RESULTS

We identified 7 cases, all of which occurred after invasive surgical procedures were performed on the affected joint, suggesting a nosocomial pattern of infection. Two patients may have been contaminated at the hospital where the M. xenopi discitis outbreak occurred. No source was identified in the other 5 patients. Despite the probable nosocomial nature of the infections, the diagnosis was delayed (mean time until diagnosis, 50 months). Repeated collection of deep tissue specimens for bacteriological analysis seemed crucial to the diagnosis. The treatment relied on combination antimicrobial therapy and surgery. Among 11 cases of M. xenopi osteoarticular infection reported in the literature from 1975 to 2005, (arthritis in 9 cases and osteitis in 2), none were nosocomial.

CONCLUSION

A high index of suspicion should be maintained to ensure the diagnosis of M. xenopi arthritis before chronic monoarthritis and before the development of irreversible joint damage.

Tuberculosis and chronic renal disease

There is an increased risk (6.9- to 52.5-fold) of tuberculosis (TB) in patients with chronic renal failure and on dialysis as compared to the general population. The symptomatology in renal patients is often insidious and nonspecific, mimicking uremic symptoms, whereas the localization is often extrapulmonary (most frequently tuberculous lymphadenitis and peritonitis). Tuberculous peritonitis makes up a large part (37%) of the total number of TB cases in continuous ambulatory peritoneal dialysis (CAPD) patients. The prognosis is very much dependent on early diagnosis and treatment. Renal physicians should be aware of the unusual presentation and localization, and include TB in the differential diagnosis of any patient having nonspecific symptoms like anorexia, fever, and weight loss. All efforts should then be made (including invasive investigations) to reach an early diagnosis, a major determinant of the outcome. However, if this is not possible or the result is negative and the diagnosis remains strongly suspected, an empirical trial with anti-TB medication is justified, especially in endemic areas. In view of the increased prevalence of the disease in the dialysis population, TB prophylaxis is recommended in those patients with a positive tuberculin (Mantoux) skin test and radiographs suggestive of old TB.

Newly described or emerging human species of nontuberculous mycobacteria

The advent of molecular testing in the laboratory has brought about the recognition of multiple newly characterized mycobacterial species not previously recognizable with most standard techniques. Some of the species are nonpathogenic, but the majority may cause clinical disease. Each is likely to have its own biology, drug susceptibility pattern, and response to drug/surgical therapy. Thus, it is important to try to recognize these new species in the laboratory. A study of the phenotypic and genotypic characteristics of these new species also may help to elucidate the epidemiology and pathogenesis of these organisms. In addition, there are multiple emerging species of nontuberculous mycobacteria including M. ulcerans, M. haemophilum, M. xenopi, and M. malmoense. [table: see text] These species are being recognized increasingly as a cause of human disease and recovered within the laboratory. The clinician must learn about these new pathogens to recognize them clinically and assist the laboratory in their recovery.

Nosocomial infections due to nontuberculous mycobacteria

Nontuberculous mycobacteria (NTM) are ubiquitous in the environment and cause colonization, infection, and pseudo-outbreaks in health care settings. Data suggest that the frequency of nosocomial outbreaks due to NTM may be increasing, and reduced hot water temperatures may be partly responsible for this phenomenon. Attention to adequate high-level disinfection of medical devices and the use of sterile reagents and biologicals will prevent most outbreaks. Because NTM cannot be eliminated from the hospital environment, and because they present an ongoing potential for infection, NTM should be considered in all cases of nosocomial infection, and careful surveillance must be used to identify potential outbreaks. Analysis of the species of NTM and the specimen source may assist in determining the significance of a cluster of isolates. Once an outbreak or pseudo-outbreak is suspected, molecular techniques should be applied promptly to determine the source and identify appropriate control measures.

Mycobacterium xenopi spinal infections after discovertebral surgery: investigation and screening of a large outbreak

BACKGROUND

Mycobacterium xenopi spinal infections were diagnosed in 1993 in patients who had undergone surgical microdiscectomy for disc hernia, by nucleotomy or microsurgery, in a private hospital. Contaminated tap water, used for rinsing surgical devices after disinfection, was identified as the source of the outbreak. Several cases were recorded in the 4 years after implementation of effective control measures because of the long time between discectomy and case detection. The national health authorities decided to launch a retrospective investigation in patients who were exposed to M xenopi contamination in that hospital.

METHODS

Mailing and media campaigns were undertaken concurrently to trace exposed patients for spinal infections. Patients were screened by magnetic resonance imaging (MRI), and the scans were reviewed by a radiologist who was unaware of the diagnosis. Suspected cases had discovertebral biopsy for histopathological and bacteriological examination.

FINDINGS

Of 3244 exposed patients, 2971 (92%) were informed about the risk of infection and 2454 (76%) had MRI. Overall, 58 cases of M xenopi spinal infection were identified (overall cumulative frequency 1.8%), including 26 by the campaign (mean delay in detection 5.2 years, SD 2.4, range 1-10 years). Multivariate analysis showed that the risk of M xenopi spinal infection was related to nucleotomy and high number of patients per operating session.

INTERPRETATION

Failures in hygiene practices could result in an uncontrolled outbreak of nosocomial infection. Patients who have been exposed to an iatrogenic infectious hazard should be screened promptly and receive effective information.