Mycobacterium Genavense Infection Research Articles

Disseminated mycobacterium genavense infection with central nervous system involvement in an HIV patient: a case report and literature review

BackgroundImmunodeficient patients, particularly HIV patients, are at risk of opportunistic infections. Nontuberculous mycobacteria can cause severe complications in immunodeficient patients.Case PresentationWe describe a 57-year-old HIV patient, primarily presented with coughs and constitutional symptoms, with a unique Mycobacterium genavense abdominal, pulmonary, and central nervous system infection, accompanied by intracranial masses.ConclusionThe diagnosis of NTM, including M. genavense, must always be considered by clinicians in immunodeficient patients, especially those with HIV, who have a compromised immune system.

Concurrent Mycobacterium genavense infection and intestinal B-cell lymphoma in a pet rabbit (Oryctolaguscuniculus)

A 6-year-old male intact pet rabbit was evaluated for chronic weight loss. A large mass was detected by palpation in the mid-abdomen and ultrasound examination suggested a jejunal location. Explorative laparotomy revealed a nodular mass within the jejunal wall. Histological examination of a biopsy revealed mycobacterial granulomatous enteritis with an atypical lymphoblastic proliferation suggestive of lymphoma. Neoplastic lymphocytes were immunopositive for Pax-5 but negative for CD3, which is diagnostic of a B-cell neoplasm. Numerous acid-fast bacteria were seen within histiocytes and identified by polymerase chain reaction as Mycobacterium genavense, which is a non-tuberculous and opportunistic mycobacterium with zoonotic potential. To the best of our knowledge, this is the first documented case of a concurrent B-cell lymphoma and M. genavense infection in a rabbit. Concomitant mycobacteriosis and lymphoma have been rarely described in animals and the coexistence of neoplasia and mycobacterial infection within the jejunum suggests a potential pathogenetic association. Interestingly, the rabbit owner worked in an anti-tuberculosis clinic, and an anthropic origin of the mycobacterial infection could not be excluded.

Mycobacterium genavense splenitis in a pet rabbit (Oryctolagus cuniculus) presented for fracture

Mycobacteriosis is an uncommon infection that has been sporadically described among wild, farmed and pet rabbits. To date, only one case of Mycobacterium genavense infection has been reported in a dwarf rabbit presenting with granulomatous pneumonia. This new case report describes granulomatous splenitis caused by M. genavense in a pet rabbit brought in for lameness caused by a femoral fracture. The initial blood test, X-ray, abdominal ultrasound, and bone marrow and spleen cytology results were consistent with a diagnosis of a metastatic giant-cell tumour. The rabbit underwent successful femoral osteosynthesis, and six months later, following the occurrence of a second spontaneous fracture and a worsening of overall health, the patient was euthanised. The postmortem histological examination showed severe granulomatous splenitis caused by acid-fast bacilli identified as M. genavense by real-time PCR analysis. The route of infection remains unknown, yet the lack of pulmonary involvement likely rules out airborne transmission. M. genavense infection, although rarely described in pet rabbits, appears to be an emerging pathogen and should be included among the differential diagnoses for pneumonia and splenomegaly.

Disseminated Mycobacterium genavense infection in an otherwise healthy child: a clinical case and literature review

This paper presents the first clinical case of combined pulmonary and abdominal M. genavense infection in an otherwise healthy, immunocompetent child with an early treatment response and full recovery. The favorable outcome was determined by rapid microbiological diagnosis using up-to-date diagnostic methods followed by targeted antimicrobial therapy.

Sarcoid-like lesions obfuscating the diagnosis of disseminated Mycobacterium genavense infection in a patient with IL-12Rβ1-associated immunodeficiency

BackgroundSarcoidosis is a systemic inflammatory disease that is characterized by non-caseating epithelioid-cell granulomas upon histology. However, similar histological findings may also be seen with certain infections. Thus, differentiation from infection is pivotal to ensure appropriate treatment. Here, we present a case of a disseminated infection with Mycobacterium genavense owing to an interleukin 12 receptor subunit beta 1 (IL-12Rβ1) associated immunodeficiency in a previously healthy female who was initially misdiagnosed with sarcoidosis. M. genavense is a nontuberculous mycobacterium which can cause lymphadenopathy, gastrointestinal and bone marrow infiltration in immunocompromised patients. With this case report we aim to highlight that an infection with M. genavense on the ground of a genetic defect of mycobacterial immune control may represent a rare differential diagnosis of sarcoidosis.Case presentationA 31-year-old female was referred to our hospital with progressive lymphadenopathy, hepatosplenomegaly, pancytopenia and systemic inflammation. She had previously been evaluated for generalized lymphadenopathy in another hospital. At that time, lymph node biopsies had revealed sarcoid-like lesions and a systemic corticosteroid treatment was initiated based on a putative diagnosis of sarcoidosis. When her condition worsened, she was transferred to our university clinic, where the diagnosis of disseminated M. genavense infection owing to an inborn interferonopathy was made. Her family history revealed that her brother had also suffered from IL-12Rβ1 deficiency and had died from a systemic infection with M. genavense at the age of 21. The patient received antimycobacterial treatment combined with subcutaneous type I interferon, which eventually led to a gradual improvement over the next months.ConclusionsDifferentiating between sarcoidosis and sarcoid-like lesions secondary to infections may be challenging, especially when pathogens are difficult to detect or not expected in an apparently immunocompetent patient. Patients with IL-12Rβ1-associated immunodeficiency may be asymptomatic until adulthood, and disseminated M. genavense infection on the grounds of an IL-12Rβ1-associated immunodeficiency may represent a rare differential diagnosis of sarcoidosis.

Disseminated Mycobacterium genavense infection in a guinea pig (Cavia porcellus): a case report

BackgroundMycobacteria are found in many environmental conditions and infect a variety of species, including rodents and rabbits. Guinea pigs are used experimentally as a model for Mycobacterium tuberculosis, but natural mycobacteriosis in guinea pigs has not been reported.Case presentationA 1.5-year-old female guinea pig was found acutely deceased with no premonitory illness. On gross post-mortem examination, multifocal to coalescing, raised, firm, pale tan nodules with discrete, irregular margins were noted over the surfaces of all lung lobes. Histopathology revealed nodules composed of clustered foamy macrophages and multinucleated giant cells containing numerous bacterial rods. Similar bacteria-laden macrophages were noted within sections of the liver, heart, palpebral conjunctiva, duodenum, and cecum. Polymerase chain reaction was performed on tissues collected during post-mortem examination. The 16S rRNA gene product was sequenced and was identical to the Mycobacterium genavense type strain.ConclusionsTo the best of the author’s knowledge, this report details the first documented case of Mycobacterium genvaense infection in a guinea pig and a follow up investigation of close-contact animals. Given their experimental susceptibility and this clinical case report, mycobacteriosis should be considered as a differential in guinea pigs exhibiting weight loss in the absence of other clinical signs. With the potential for zoonotic transmission in immunosuppressed individuals, precautions should be taken to safeguard human health in cases of guinea pigs with suspected M. genavense infection.

Morbidity in an adenosine deaminase-deficient patient during 27 years of enzyme replacement therapy

IntroductionAdenosine deaminase (ADA) deficiency causes severe immunodeficiency that is lethal in infancy. Enzyme replacement therapy (ERT) can improve the metabolic, immune and non-immune abnormalities in patients prior to transplantation, however, its benefits over extended periods are not well characterized.We describe a 28-year-old female who received ERT for 27 years. She suffered from EBV negative B cell lymphoma of the hip at 14 years of age and Guillian-Barre Syndrome 2 years later. At 22 years of age, she experienced a gastrointestinal infection with Mycobacterium genavense. At 26 years of age, lymphoma reoccurred with multiple liver lesions followed by Mycobacterium genavense infection with dissemination to the brain. Throughout this period, ADA activity in the plasma was within the therapeutic range. Repeated evaluations demonstrated very low lymphocyte counts and impaired T cell function. ConclusionsERT might be insufficient to maintain normal immunity over extended periods in some ADA-deficient patients.

An unusual case of abdominal mycobacterial infection: Case report and literature review.

This article presents a case of an HIV-infected paediatric patient with an unusual Mycobacterium genavense infection with predominantly abdominal organ involvement.

Sclerosing mesenteritis by Mycobacterium Genavense mimicking a lymphoproliferative syndrome: The value of 18F-FDG PET/CT

A 39-year-old man with HIV presented fever, hepatosplenomegaly and mesenteric and retroperitoneal enlarged lymph nodes in abdominal CT (Fig. 1a,b), so a lymphoproliferative syndrome was suspected. Therefore a 18F-FDG PET/CT (Fig. 1c) was requested to assess the initial staging and to locate the most accessible adenopathy for biopsy, revealing high uptake of FDG in mesenteric and retroperitoneal lymph nodes, spleen and bone marrow involvement, and normometabolic hepatomegaly. The biopsy of mesenteric adenopathies excluded lymphoma and confirmed the diagnosis of Mycobacterium Genavense (MG) infection.

Disseminated Mycobacterium genavense Infection in Patient with Adult-Onset Immunodeficiency

We report a case of disseminated Mycobacterium genavense infection resulting from neutralizing anti–interferon-γ autoantibodies in the patient. We identified M. genavense targeting the hsp65 gene in an aspiration specimen of the lymph node. Adult-onset immunodeficiency caused by neutralizing anti–interferon-γ autoantibodies, in addition to HIV infection, can lead to disseminated nontuberculous mycobacterial infection.

Mycobacterium genavense infection in two species of captive snakes.

Background Mycobacterium is an important zoonotic agent with companion, livestock and wildlife animals reportedly playing a role as reservoirs. Although its association with reptiles has been described, the disease cycle remains to be fully established, particularly in snakes. Accordingly, this study aimed to report the occurrence of mycobacteriosis with clinical pneumonia in one exotic python snake (Python molurus) and one native green snake (Philodryas olfersii) from the Sorocaba Zoo, São Paulo state, Brazil.MethodsDiagnosis was based on necropsy, histopathological examination, Ziehl-Neelsen stain and immunohistochemistry.ResultsUsing a nested PCR followed by DNA sequencing and bioinformatics analysis, the causative Mycobacterium species was identified as Mycobacterium genavense.Conclusion Mycobacterium genavense is an infectious zoonotic agent of animal and public health concerns.

Immune reconstitution inflammatory syndrome due to Mycobacterium genavense in an HIV-infected patient: Impact of rapid species identification by rpoB sequencing on clinical management

Introduction: Diagnosis of infections due to Mycobacterium tuberculosis has been recently facilitated with the worldwide implementation of rapid molecular tests. However, the diagnosis of non-TB mycobacteria (NTM) remains a major challenge for laboratories, as this group of bacteria contains over 150 different species with highly variable bacteriological properties. The development and implementation in clinical practice of techniques allowing rapid identification of NTM at the species level is, therefore, important for clinical laboratories. We report the case of an HIV-1 positive patient presenting with severe NTM infection who benefited from a novel rapid diagnostic technique, based on the direct sequencing of the rpoB gene from smear-positive clinical samples. Case Presentation: A 43-year-old HIV-1 positive woman was hospitalized for bicytopenia in the presence of an inflamed supraclavicular lymph node. The diagnosis of disseminated Mycobacterium genavense infection, which involved the bone marrow and several lymph nodes, was missed by conventional mycobacteriological techniques. Identification was obtained by performing direct sequencing of the rpoB gene. Conclusion: We describe a novel technique that allows the rapid diagnosis of NTM infections directly from biological samples. This technique is now implemented in our routine workflow for smear and culture-positive samples, after the exclusion of TB, by rapid molecular assays.

An outbreak of Mycobacterium genavense infection in a flock of captive diamond doves (Geopelia cuneata).

Two diamond doves (Geopelia cuneata) in a flock of 23 birds housed in an aviary in a zoo in central Japan were found dead as a result of mycobacteriosis. Fecal samples of the remaining doves were positive for mycobacterial infection, and thus they were euthanatized. Clinical signs and gross pathology, including weight loss and sudden death and slight enlargement of the liver and intestine, were observed in a small number of birds (3/23). Disseminated histiocytic infiltration of either aggregates or sheets of epithelioid cells containing acid-fast bacilli, in the absence of caseous necrosis, were observed in different organs of the infected doves, especially lungs (23/23), intestines (9/23), livers (7/23), and hearts (6/23). Mycobacterium sp. was isolated from the livers of three birds (3/23). DNA extracted from frozen liver and formalin-fixed, paraffin-embedded tissues (5/23) were used for amplification of the gene encoding mycobacterial 65-kDa heat shock protein (hsp65). The causative Mycobacterium species was identified by PCR-restriction fragment length polymorphism analysis. Mycobacterium genavense infection was confirmed in three of the diamond doves. Moreover, partial 16S rDNA gene sequencing revealed 100% identity across the three samples tested, and 99.77% nucleotide homology of the isolate sequence to M. genavense. The main route of M. genavense infection in the diamond doves was most likely airborne, suggesting a potential zoonotic risk of airborne transmission between humans and birds.

Disseminated Mycobacterium genavense infection in a patient with immunosuppressive therapy and lymphoproliferative malignancy

We present the case of a 51-year-old woman who presented a right supraclavicular mass corresponding to lymphadenitis with atypical mycobacterium (Mycobacterium genavense). Later, she developed subcutaneous purulent small nodules containing the same germ. The presence of this mycobacterium was in the context of recurrent peripheral T-cell lymphoma and immunosuppressive therapy for seronegative inflammatory polyarthritis.

Mycobacterium genavense specific mesenteritic syndrome in HIV-infected patients

Abdominal mesenteritis is a rare and poorly understood gastroenterological disease. Here, we report on two identical cases of Mycobacterium genavense associated retractile mesenteritis in HIV-positive patients. A literature search retrieved only few small retrospective studies, which characterize the clinical course of this seldom infection. We propose a pathogen-specific syndrome of retractile mesenteritis in HIV-positive patients linked to Mycobacterium genavense infection on the basis of our clinical observation and literature meta-analysis with duodenal wall thickening, central mesenterial mass and vascular complications.

Mycobacterium genavense specific mesenteritic syndrome in HIV-infected patients - an new entity of retractile mesenteritis?

Background: Abdominal mesenteritis is an neglected and poorly understood gastroenterological disease. Here we report on two identical cases of Mycobacterium genavense associated retractile mesenteritis in HIV-positive patients. Literature search retrieved only few small retrospective studies, which characterize the clinical course of this rare infection. On the basis of our clinical observation and literature data, we propose a pathogen specific syndrome of retractile mesenteritis in HIV-positive patients linked to Mycobacterium genavense infection with duodenal wall thickening, central mesenterial mass and vascular complications.

Duodenal Mycobacterium genavense infection in a patient with acquired immunodeficiency syndrome

Duodenal Mycobacterium genavense infection in a patient with acquired immunodeficiency syndrome

Disseminated Mycobacterium genavense infection after immunosuppressive therapy shows underlying new composite heterozygous mutations of β1 subunit of IL-12 receptor gene

Disseminated Mycobacterium genavense infection after immunosuppressive therapy shows underlying new composite heterozygous mutations of β1 subunit of IL-12 receptor gene

Relapsing Mycobacterium Genavense Infection as a Cause of Late Death in a Lung Transplant Recipient: Case Report and Review of the Literature

Mycobacterium genavense is recognized as a life-threatening pathogen in severely immunocompromised patients, mostly in those with advanced human immunodeficiency virus infection. We report a case of M. genavense infection in a lung-transplant recipient with late-onset death occurring from disseminated infection. In human immunodeficiency virus-negative patients, there exist only about 10 reports of disseminated M. genavense infection in immunocompromised hosts; and to our knowledge, this is a first reported case of M. genavense infection after a lung transplant. Diagnosis of M. genavense was obtained only with nucleic acid-based identification technique, as frequently observed in a few cases of human immunodeficiency virus-negative patients. A striking feature was the recurrence of this infection in our patient after a seemingly infection-free period of 3 years. Because M. genavense infection can be life-threatening, clinicians must be aware of the frequent requirement for nucleic-acid-based identification for its diagnosis.

Disseminated Mycobacterium genavense infection in a patient with a novel partial interleukin-12/23 receptor β1 deficiency

A patient presented with late onset disseminated nontuberculous mycobacterium (NTM) infection due to a novel interleukin-12/interleukin-23 receptor β1 (IL-12/IL-23Rβ1) mutation, r.1561C>G, leading to the amino acid substitution R521G. This is the second patient reported with a partial IL-12/IL-23Rβ1 defect.