Spondylitis Due to Mycobacterium xenopi in a Human Immunodeficiency Virus Type 1-Infected Patient: Case Report and Review of the Literature

Abstract

Nontuberculous mycobacterial infections are well known to occur in patients with human immunodeficiency virus infection. However, spondylitis due to mycobacteria other than Mycobacterium tuberculosis is uncommon. We report a case of biopsy-and culture-proven Mycobacterium xenopi spondylitis in an AIDS patient and discuss approaches to diagnosis and therapy. This case serves to highlight the potential pathogenic role of this usually environmental commensal organism in severely immunosuppressed AIDS patients and uncertainties in their management, given the scarce data on appropriate therapy for this organism. CASE REPORTA 42-year-old man was diagnosed with AIDS in 1998 when he presented with Pneumocystis carinii pneumonia. Over the next few years, he developed several other opportunistic infections, as he was not adherent to antiretroviral therapy. In August 2003, he was admitted for cellulitis on the right side of his face. On admission, neurological examination found static cerebellar syndrome associated with kinetic gait instability. No sensory or motor deficit was found. The rest of the physical results were normal. Laboratory studies revealed normal full blood count, except for lymphopenia. The CD4 T-lymphocyte count was 41/mm 3 . Renal function and hepatic biology were within the normal limits. Three blood cultures were negative. Cerebral computed tomography (CT) scan showed several bilateral cortical hypodensities of frontal and temporal regions without enhancing after contrast product injection. Cerebral magnetic resonance imaging (MRI) revealed T2-weighed images without enhancing after gadolinium injection in the same areas. Cerebrospinal fluid showed 1 white blood cell as well as a protein level of 0.62 g/liter and a glucose level of 3 mmol/liter (serum level, 5.8 mmol/liter), and cultures were negative. The patient received intravenous oxacillin and needed surgical drainage for a facial soft-tissue abscess. Oxacillin was continued for 10 days. A presumptive standard treatment regimen against Toxoplasma gondii encephalitis was started, considering neurological signs and intracerebral abnormalities during CT scan and MRI. Progress was satisfactory at first, but after 2 weeks our patient developed sudden flaccid paralysis of both legs with a T8 sensory level. MRI of the spine revealed signs of spondylitis at the T7 to T8 level, with a locally compressing epidural mass and an anterolateral paraspinal soft-tissue-associated inflammatory process. Transoesophageal echocardiography showed no signs of endocarditis. A CT-guided vertebral biopsy was performed. Gram and acid-fast stains showed no organism, and standard bacterial cultures were negative after 48 h. Histology of the specimen showed nonspecific inflammation. Supposing that Staphylococcus aureus could be responsible for T7 to T8 spondylitis given the recent history of facial cellulitis, rifampin (600 mg twice a day) and ofloxacin (400 mg twice a day) were started after oxacillin was discontinued. Retrospective studies with chest X-rays taken 2 months ea...

Non-tuberculous mycobacteria in the sputum of HIV-infected patients: infection or colonization?

“…The result of this study and others suggest that isolation of M. xenopi should be generally considered nonpathogenic, although case reports have described infections with this microorganism in HIV-infected patients. 8,9 Nevertheless, in patients with chronic pulmonary disease, isolation of M. xenopi can be clinically relevant. 10 The American Thoracic Society guidelines for the diagnosis and treatment of NTM infections in 2007 established that it is necessary to fulfil clinical, bacteriological and radiological criteria for the diagnosis of NTM pulmonary disease.…”

Mycobacterium xenopiClinical Relevance and Determinants, the Netherlands

“…Also, because most HIV-infected patients receive highly active antiretroviral therapy, fewer cases of severe HIV immunosuppression and its co-infections are seen. HIV infection predisposes patients to extrapulmonary M. xenopi infection, especially spinal infection (6,19). Those with HIV-associated spinal M. xenopi infection had rising CD4 counts after starting or changing highly active antiretroviral therapy regimens (Table 1).…”

Molecular Characterization of Mycobacterial Ribonucleotide Reductase (RNR) and its Implication as a Novel Drug Target

“…Nearly one third of known Mycobacterium species have been observed to be associated with disease in humans [16]. The species of NTM associated with human disease are : M. avium, M. intracellulare [17,18], M. kansasii [19], M. paratuberculosis [20], M. scrofulaceum [21], M. simiae [22,23], M. interjectum [24], M. xenopi [25], M. szulgai [26], M. fortuitum [27], M. chelonae [28], M. marinum [29], M. genavense [30], M. ulcerans [31], M. smegmatis [32], M. thermoresistible [33], M. neoaurum [34], M. vaccae [35]. Presently little information is available on the evolution of RNR in different species of Mycobacterium which governs the central metabolic pathways by directing the DNA replication.…”