Disseminated Mycobacterium genavense infection: clinical and microbiological features and response to therapy

OBJECTIVE: Mycobacterium genavense is a newly described pathogen that causes disseminated infection in AIDS. It is difficult to detect and identify due to its slow growth and fastidious nature. There is little information available about therapy for this new pathogen. We describe clinical and laboratory features and response to therapy in four patients with advanced AIDS complicated by disseminated M. genavense infection from Denver, Colorado, USA. DESIGN AND METHODS: Retrospective analysis of four cases identified in an AIDS clinic affiliated with a municipal hospital in Denver, Colorado. Clinical samples were inoculated onto BACTEC 12B, Lowenstein-Jensen, and Middlebrook 7H11 media. RESULTS: The clinical features mimicked those of disseminated M. avium complex infection, with invasion of liver, spleen and lymph nodes with acid-fast bacilli (AFB). Acid-fast smears of blood and lymph nodes were positive; there was a modest increase in the growth index in BACTEC broth and tiny colonies appeared on Middlebrook agar. Patients were treated with combinations of antimycobacterial agents. Blood smears and cultures reverted to negative in treated patients. The best clinical response was associated with clarithromycin therapy. CONCLUSIONS: Disseminated disease due to M. genavense should be suspected among patients with the clinical presentation of disseminated M. avium complex infection and low growth index on BACTEC cultures for AFB. The diagnosis of M. genavense may be facilitated by performing acid-fast stains of samples from BACTEC bottles in such individuals. Clarithromycin therapy is associated with clinical improvement and clearance of bacteremia.     

Mycobacterium genavense infection in 2 HIV seropositive patients in Amsterdam

Two patients with an HIV-I infection, a man aged 47 with confusion, aphasia and diarrhoea, and a man aged 32 with dysphagia, a non-productive cough and diarrhoea, were diagnosed as having a disseminated Mycobacterium genavense infection. Both had low counts of CD4+ T lymphocytes. They responded to antimycobacterial treatment. M. genavense was recognized in Geneva in the early nineties as a causative agent of disseminated mycobacterial infections in HIV-seropositive patients with poor cellular immunity. The clinical picture resembles that of a generalized infection with M. avium-intracellulare. M. genavense is a slowly growing mycobacterium which can be isolated and identified using enriched nutrient media and molecular-biological techniques. The infection probably begins in the gastrointestinal tract after oral contamination. DNA of M. genavense can be demonstrated in 25% of the intestinal biopsy samples of non-HIV-seropositive patients.     

Mycobacterium genavense infection presenting as a solitary brain mass in a patient with AIDS: case report and review

Patients with AIDS are prone to developing infections with opportunistic pathogens. Recently, a new mycobacterium, Mycobacterium genavense, has been found to cause infection in patients with AIDS. Previously published reports indicate that patients who are infected with this organism present with the same clinical features as do patients with disseminated infection due to organisms of the Mycobacterium avium complex. We describe an unusual case of a patient with AIDS who presented with grand mal seizures and a mass lesion in his brain, which was found to be caused by infection with M. genavense. No evidence of disseminated infection could be found in this patient. We discuss the microbiology of this organism and review the literature on M. genavense infections. Clinicians should be aware of this organism so that efforts at culture and identification will be made.     

Mycobacterium genavense infections in pet animals

Mycobacterium genavense, a recently reported cause of a wasting illness in patients with AIDS, was isolated from a cervical lymph mode from a dog with severe hind limb weakness and from trachael tissue from a parrot with acute onset respiratory distress. Physicians caring for immunocompromised patients should consider birds and dogs potential sources of M. genavense infection and submit appropriate specimens for culture.     

Disseminated acanthamoeba infection in patients with AIDS: case reports and review

Acanthamoeba infection has been described as an opportunistic infection in persons with AIDS. We report two cases of patients with AIDS and acanthamoeba infection and review the manifestations of this protozoan infection in patients infected with human immunodeficiency virus. The diagnosis of this infection requires a high index of suspicion because the clinical and histologic manifestations may be confused with those of disseminated fungal or algal disease. Clinicians and laboratory personnel should be aware of this potentially fatal condition so that appropriate diagnostic studies can be performed and treatment can be urgently administered. Early initiation of therapy may alter the clinical outcome of the disease.     

Mycobacteriosis due to Mycobacterium genavense in six pet birds

Six cases of mycobacteriosis due to Mycobacterium genavense in three budgerigars (Melopsittacus undulatus), one orange-winged amazon (Amazona amazonica), one flycatcher (Cyanoptila cyanomelana), and one zebra finch (Taeniopygia guttata) are discussed. Gross lesions associated with the infection included a high degree of muscular wasting (five cases), hepatomegaly (four cases), and thickening of the wall of the small intestine (four cases). Granulomas were found in the lung (one case) and the subcutis (one case). Acid-fast bacilli were detected in the liver of all six birds. Only the use of acidic BACTEC mediums consistently led to growth, whereas the egg-based medium failed. These findings point to a possible role of the environment as a reservoir for M. genavense.     

Parvovirus B19 infection in AIDS patients

We report a 16-year-old boy, born to consanguineous parents, with mental retardation, gait disturbances and dysarthria; brain magnetic resonance showed features consistent with rhombencephalosynapsis. This condition is characterised by a hypoplastic single-lobed cerebellum. The interest of this case is the presence of common ancestors, pointing to an autosomal recessive inheritance of the malformation.     

Haemolysin from Mycobacterium avium complex isolates from AIDS patients

OBJECTIVES: 856 cases of hypospadias, operated over a period of 7 years, using various methods of one-stage repair, are reviewed in order to assess their functional and cosmetic results and their rate of complications. PATIENTS AND METHODS: 856 boys with an average age of 3.5 years were classified according to the classification proposed by Duckett (anterior, middle and posterior hypospadias). Magpi, Mathieu's (flip-flap technique) and pedicled flaps tubularized or as onlay were utilized, depending upon the severity of the anomaly. RESULTS: Satisfactory functional and cosmetic results without complications were obtained in 736 cases (85.9%). We had early complications with 72 cases consisting of 64 fistulas (7. 5%) and 8 cases of breakdown (0.93%), and 48 cases of delayed complications consisting of 26 meatal retractions (3.1%) and 22 cases of meatal stenosis (2.5%).     

Mycobacteriosis caused by Mycobacterium genavense in birds kept in a zoo: 11-year survey

Nucleotide sequences encoding GroEL homologs of intracellular symbionts in three closely interrelated aphids were compared with one another and that for GroEL. It was suggested that in these proteins a particular position is highly susceptible to amino acid substitution, through which the GroEL homologs of symbionts seemed to have acquired a unique function on top of the activity as molecular chaperone. This may represent a rare example of non-neutral evolution of molecule under the positive selection pressure.     

Disseminated miliary tuberculosis of the skin in patients with AIDS: report of four cases

During the course of long-term follow-up, we examined the efficacy of interferon (IFN) in the improvement of liver function and prevention of hepatocellular carcinoma (HCC) in hepatitis C virus (HCV) associated cirrhosis patients. Fifty-five cirrhotic patients, in whom HCC nodules in the liver were not detected by ultrasonography (US) or computed tomography (CT), received 3 or 6 million units of human lymphoblastoid IFN daily for two weeks and 3 times a week for 22 weeks. Complete response (CR) was defined as normalization of serum alanine aminotransferase (ALT) together with negative HCV RNA at 6 months after IFN therapy completion. Any other pattern of response was defined as non-response (NR). After IFN therapy the patients were followed up every 1-3 months for at least 1 year (average follow-up period, about 40 months) with serological tests and US or CT. In the 8 CR patients, the serum ALT levels remained normal and HCV RNA remained negative. Platelet count, white blood cell count, serum albumin and zinc turbidity test have recovered to the normal range at final follow-up. Ten of the 47 patients with NR have developed HCC, whereas no patients with CR has developed HCC during follow-up. We conclude that IFN improves the liver function and may prevent the development of HCC even in cirrhotic patients who show CR to IFN therapy.     

Disseminated infection with Trichosporon asahii

Trichosporon fungaemia and disseminated, purpuric, papular skin lesions developed on the head, trunk and extremities of a 5-year-old female with acute lymphocytic leukaemia. Histopathologically, the skin lesions demonstrated dermal budding yeasts. She died despite treatment with antifungal drugs. The isolate from the blood was further identified morphologically and physiologically as Trichosporon asahii, based on the revision of the genus Trichosporon by Guého et al. (1992). According to the new revision, T. asahii is the only taxon regularly involved in systemic mycoses, so that most of the isolates previously reported as T. beigelii (formerly, T. cutaneum) in human deep mycoses are now thought to belong to T. asahii.     

Tuberculosis cutis miliaris disseminata due to multidrug-resistant Mycobacterium tuberculosis in AIDS patients

Two patients with AIDS and disseminated tuberculosis characterized by cutaneous involvement are reported. They developed a maculopapular skin eruption, from which a multidrug-resistant Mycobacterium tuberculosis strain was isolated. In both cases the clinical course was rapidly fatal. Tuberculosis cutis miliaris disseminata should be differentiated from the skin lesions frequently seen in HIV-infected patients, especially from folliculitis. In patients with tuberculosis, the appearance of cutaneous lesions may be due to the haematogenous dissemination of mycobacteria. Therefore, early identification of the causative organism by use of optimal microbiological methods is fundamental.     

Disease caused by Mycobacterium kansasii in patients with HIV infection

BACKGROUND: To describe the clinical features and response to therapy in Mycobacterium kansasii disease among HIV infected patients, an increasing problem in our setting. METHODS: A retrospective survey of all charts from patients with HIV infection with Mycobacterium kansasii infection recorded between April 1985 and December 1991. RESULTS: A total of 13 patients were identified. All of them had clinically significant respiratory tract samples with a definite M. kansasii isolation. Only three had disseminated disease. In all but two cases, CD4 cell count at diagnosis time was lower than 200/mm3. Chest X-ray films showed interstitial pattern (8 cases) or alveolar condensation (3 cases) and lung cavities were seen in 4 patients. All patients with lung disease and one with disseminated disease responded well to anti-tuberculous therapy. CONCLUSION: Mycobacterium kansasii produces disease in advances stages of HIV-induced immunosuppression. The most common primary location is pulmonary, but disseminated forms can also be seen. The infection can be controlled with standard anti-tuberculous therapy.