Early diagnosis of disseminated Mycobacterium genavense infection

Drug Susceptibility of Non-tuberculous Strains of Mycobacterium Isolated from Birds from Poland

Mycobacterioses are a constant problem in backyard poultry, as well as pet birds. To date, no evidence of direct transmission of atypical bacilli between humans has been demonstrated, but it cannot be ruled out that sick animals can be a source of infection for people in their environment. The aim of the study was to identify mycobacteria isolated from birds with diagnosed mycobacteriosis and to determine the susceptibility of mycobacterial isolates from these animals to antituberculous drugs most commonly used in the treatment of mycobacterial infections in humans. For drug susceptibility tests, drugs such as isoniazid, rifampicin, streptomycin, ethambutol, ofloxacin, capreomycin, cycloserine and ethionamide were used. A high degree of drug resistance was demonstrated, particularly in Mycobacterium avium . Isolates of Mycobacterium xenopi showed a relatively good susceptibility to the drugs tested. The drug resistance of Mycobacterium genavense has not been determined, but this mycobacterium was identified in ten cases, which is the second most frequent occurrence in the cases studied.

Mycobacterioses are a constant problem in backyard poultry, as well as pet birds. To date, no evidence of direct transmission of atypical bacilli between humans has been demonstrated, but it cannot be ruled out that sick animals can be a source of infection for people in their environment. The aim of the study was to identify mycobacteria isolated from birds with diagnosed mycobacteriosis and to determine the susceptibility of mycobacterial isolates from these animals to antituberculous drugs most commonly used in the treatment of mycobacterial infections in humans. For drug susceptibility tests, drugs such as isoniazid, rifampicin, streptomycin, ethambutol, ofloxacin, capreomycin, cycloserine and ethionamide were used. A high degree of drug resistance was demonstrated, particularly in Mycobacterium avium. Isolates of Mycobacterium xenopi showed a relatively good susceptibility to the drugs tested. The drug resistance of Mycobacterium genavense has not been determined, but this mycobacterium was identified in ten cases, which is the second most frequent occurrence in the cases studied.

Mycobacterium genavense infections in non-HIV immunocompromised hosts: a systematic review

BACKGROUND

Mycobacterium genavense is a non-tuberculous mycobacterium which can rarely cause disease in non-HIV immunocompromised hosts. We describe our experience with this unusual infection and perform a systematic review of the literature to describe the features of M. genavense infection in non-HIV immunocompromised hosts.

METHODS

All cases of Mycobacterium genavense infection in non-HIV patients at our institution were reviewed. In addition, we conducted a systematic review of the literature to identify previously published cases of M. genavense infections in non-HIV hosts.

FINDINGS

Two cases of M. genavense were identified at our center; a 51-year-old renal transplant recipient with a prosthetic knee joint infection and a 66-year-old woman with idiopathic CD4 lymphocytopenia with gastrointestinal tract disease. The systematic review identified 44 cases of M. genavense infection in non-HIV hosts. The most common underlying conditions were solid organ transplantation (40%), sarcoidosis (14%) and hematopoietic stem cell transplantation (7%). Disease most commonly involved the gastrointestinal tract, spleen, liver or bone marrow. Diagnosis was challenging with PCR required for identification in nearly all cases. Over one-third of patients died, which may reflect the combination of infection and underlying comorbidities. Overall cure was achieved in 61% with a mean duration of antimycobacterial therapy of 15.5 months (range 10-24).

CONCLUSION

M. genavense infection is a rare mycobacterial infection in non-HIV immunocompromised hosts. It should be suspected in immunocompromised patients presenting with disseminated mycobacterial infection, acid fast bacilli on smear or histopathologic examination, with poor or no growth in mycobacterial cultures.

Mycobacterium genavenseinvading the bone marrow in a HIV-positive patient

Nontuberculous mycobacteria infrequently cause disseminated infections in immunocompetent hosts. However, they are increasingly being recognized in immunocompromised patients. We present the case of a 40‐year‐old HIV‐positive male presenting with lymphadenopathies and pancytopenia in whom disseminated infection, with bone marrow involvement by Mycobacterium genavense (M. genavense) was diagnosed.

Mycobacterium genavense-induced spindle cell pseudotumor in a pediatric hematopoietic stem cell transplant recipient: Case report and review of the literature

We describe the first reported pediatric patient to our knowledge with a spindle cell pseudotumor caused by Mycobacterium genavense in a hematopoietic stem cell transplant recipient, and review the literature of such an entity in the transplant population.

Non-tuberculous mycobacterial infections in solid organ transplant recipients: An update

Non-tuberculous mycobacteria are ubiquitous environmental organisms that are now increasingly recognized as important causes of clinical disease in solid organ transplant recipients. Risk factors of non-tuberculous mycobacteria infection are severe immunologic defects and structural abnormalities. Lung transplant recipients are at higher risk for non-tuberculous mycobacterial disease compared to recipients of other solid organs. The clinical presentation could be skin and soft tissue infection, osteoarticular disease, pleuropulmonary infection, bloodstream (including catheter-associated) infection, lymphadenitis, and disseminated or multi-organ disease. Management of non-tuberculous mycobacteria infection is complex due to the prolonged treatment course with multi-drug regimens that are anticipated to interact with immunosuppressive medications. This review article provides an update on infections due to non-tuberculous mycobacteria after solid organ transplantation, and discusses the epidemiology, risk factors, clinical presentation, and management.

Mycobacterium genavense Infections in a Tertiary Hospital and Reviewed Cases in Non-HIV Patients

Mycobacterium genavense is a relatively new species of nontuberculous mycobacterium reported to cause disseminated infections in patients with AIDS and later on in non-HIV immunosuppressed patients. We describe clinical and laboratory features and response to therapy in 7 patients, three of them with HIV infection and four non-HIV-three organ transplant recipients and one with hyper-IgE syndrome-in Valencia, Spain, in a ten years period. We then summarize the published cases of M. avium complex infection, with invasion of peripheral blood, liver, spleen, bone marrow, lymph nodes, and lungs. In clinical samples a large number of acid-fast bacilli were observed. M. genavense grew only from liquid media and after a prolonged incubation period. Its identification was accomplished through molecular methods. Patients were treated with prolonged combinations of antimicrobial agents. There was clinical favourable outcome in 4 patients.

Mycobacterium genavense in the Netherlands: an opportunistic pathogen in HIV and non-HIV immunocompromised patients. An observational study in 14 cases

Mycobacterium genavense is an opportunistic non-tuberculous mycobacterium previously mostly associated with HIV-infected patients with CD4 counts below 100/μL. In this retrospective observational study of medical charts we studied all Dutch patients in whom M. genavense was detected between January 2002 and January 2010. Of the 14 patients identified, 13 (93%) showed clinically relevant M. genavense disease. All patients with M. genavense disease were severely immunocompromised, including HIV-infected patients, solid organ transplant recipients, those with chronic steroid use in combination with other immune modulating drugs, recipients of chemotherapy for non-Hodgkin lymphoma, and those with immunodeficiency syndromes. Two patients had non-disseminated pulmonary M. genavense disease. Of the 12 patients treated, eight (75%) showed a favourable outcome. Four patients died in this study, three despite treatment for M. genavense disease. We conclude that M. genavense is a clinically relevant pathogen in severely immunocompromised patients that causes predominantly disseminated disease with serious morbidity and mortality. M. genavense is increasingly seen among non-HIV immunocompromised patients.

Mycobacterium genavense as a cause of subacute pneumonia in patients with severe cellular immunodeficiency

BACKGROUND

Mycobacterium genavense is a rare nontuberculous mycobacteria (NTM). Human infections are mostly disseminated in the setting of the AIDS epidemic or the use of aggressive immunosuppressive treatments. M. genavense culture is fastidious, requiring supplemented media. Pulmonary involvement rarely occurs as a primary localization.

CASES PRESENTATION

We report here two patients with pneumonia as the predominant manifestation of M. genavense infection: one kidney transplanted patient and one HIV-infected patient. Both patients were initially treated with anti-tuberculous drugs before the identification of M. genavense on sputum or broncho-alveolar lavage fluid culture. A four-drug regimen including clarithromycin and rifabutin was started. Gamma interferon has been helpful in addition to antimycobacterial treatment for one patient.

CONCLUSION

Clinicians should be aware that M. genavense could be the etiologic agent of sub-acute pneumonia mimicking tuberculosis in patients with cellular immunodeficiency status.

Mycobacterium genavense infections: a retrospective multicenter study in France, 1996-2007

Mycobacterium genavense, a nontuberculous mycobacterium, led to devastating infections in patients with acquired immunodeficiency syndrome (AIDS) before highly active antiretroviral therapy (HAART) was available, as well as in other immunocompromised patients. We conducted the current study to describe the features of this infection in patients infected with human immunodeficiency virus (HIV) in the HAART era and in non HIV-infected patients.We conducted a retrospective cohort survey in France. All patients with M. genavense infection diagnosed from 1996 to 2007 at the National Reference Center, Institut Pasteur, Paris, were identified and their clinical, laboratory, and microbiologic data were centralized in a single database. Twenty-five cases of M. genavense infection originating from 19 centers were identified. Twenty patients had AIDS, 3 had solid organ transplantation, and 2 had sarcoidosis. Sixty-four percent (n = 16) were male, mean age was 42 years, and median CD4 count was 13/mm (range, 0-148/mm) in patients with AIDS. Twenty-four patients had disseminated infection with fever (75%, n = 18), weight loss (79%, n = 19), abdominal pain (71%, n = 17), diarrhea (62.5%, n = 15), splenomegaly (71%, n = 17), hepatomegaly (62.5%, n = 15), or abdominal adenopathy (62.5%, n = 15). M. genavense was isolated from the lymph node (n = 13), intestinal biopsy (n = 9), blood (n = 6), sputum (n = 3), stool (n = 3), and bone marrow (n = 5). Eleven patients (44%) died, 8 (32%) were considered cured with no residual symptoms, and 6 (24%) had chronic symptoms. The 1-year survival rate was 72%.The prognosis of M. genavense infection in HIV-infected patients has dramatically improved with HAART. Clinical presentations in HIV and non-HIV immunocompromised patients were similar.

Detection of Mycobacterium tuberculosis complex organisms in the stools of patients with pulmonary tuberculosis

The laboratory diagnosis of pulmonary tuberculosis mainly relies on the detection of Mycobacterium tuberculosis complex (MTC) organisms in the sputum. In patients who do not give sputum, alternative respiratory tract specimens can be obtained only by invasive procedures. Based on the known survival of MTC organisms in the gastric fluid, we hypothesized that swallowed MTC organisms would be detectable in stool samples. We compared the presence of MTC organisms in respiratory tract specimens and stool specimens collected in parallel from the same patients. MTC was detected in cultures grown on egg-based medium after appropriate decontamination, by microscopic examination after Ziehl–Neelsen staining and by real-time PCR detection of IS6110 using internal controls. A case of pulmonary tuberculosis was defined by the presence of (i) clinical and radiological signs and symptoms suggestive of pulmonary tuberculosis, and (ii) culture of MTC organisms from at least one respiratory tract specimen or (iii) the presence of acid-fast bacilli in the sputum that were subsequently identified as MTC organisms by real-time PCR. The observation of 134 patients suspected to be suffering pulmonary tuberculosis led to the identification of 24 cases and 110 non-infected control patients. Cases and controls did not significantly differ with respect to sex but cases were significantly younger than controls. The sensitivity/specificity was 37.5 %/100 % for the microscopic examination of stools, 54.2 %/100 % for culturing and 100 %/97.3 % for real-time PCR. The positive predicted value was 100 %, 100 % and 88.9 %, respectively, and the negative predicted value was 88 %, 90.9 % and 100 %, respectively. In four patients, a stool specimen initially yielded the correct diagnosis of pulmonary tuberculosis before evaluation of the respiratory tract specimen confirmed the diagnosis. These data indicate that stools could be used in conjunction with sputum testing or as an alternative specimen upon which to base the diagnosis of pulmonary tuberculosis by molecular identification of acid-fast bacilli and culture. This non-invasive alternative procedure is of particular interest for patients who cannot expectorate.

Infection with Mycobacterium genavense in a patient with systemic lupus erythematosus

A 55-year-old woman with systemic lupus erythematosus was admitted with fever of unknown origin. She had been on an immunosuppressive regimen for the past 8 years including steroids and Azathioprine. Laboratory parameters revealed a markedly elevated C-reactive protein of 189 mg/l, antinuclear antibodies of 1:2,560, a hemoglobin level of 9.0 g/dl, and a severe lymphopenia (total lymphocytes 49.4/microl, CD4(+) cells 2/microl, CD8(+) cells 7/microl). Neither blood culture samples nor computed tomography and magnetic resonance imaging of the chest and abdomen nor a trans-esophageal echocardiography revealed positive results. A bone marrow biopsy did not show signs of hematologic disease, but revealed a small granuloma rife with acid-fast bacilli, which were later confirmed to be Mycobacterium genavense by gene sequencing. To our knowledge, this is the first case involving M. genavense infection in a patient with systemic lupus erythematosus. In contrast to other reports regarding disseminated M. genavense infection, the patient is still alive and well.