Septic Arthritis Caused by Mycobacterium Kansasii in a Bone Marrow Transplant Recipient.

We report an 18-year-old female individual with septic arthritis due to Mycobacterium kansasii. Three years and 6 months before arthritis, the patient underwent bone marrow transplantation and developed severe chronic graft-versus-host disease. The arthritis was refractory to medication, and she underwent joint lavage of the right foot, hip joint, and elbow joint. After surgery, her joint symptoms were relieved, and chronic graft-versus-host disease remitted more easily. It is important that we maintain a high index of suspicion for mycobacterial arthritis and diagnose it early when immunosuppressed patients experience chronic pain and joint swelling.

Crystal structure of a hemerythrin-like protein from Mycobacterium kansasii and homology model of the orthologous Rv2633c protein of M. tuberculosis.

Pathogenic and opportunistic mycobacteria have a distinct class of non-heme di-iron hemerythrin-like proteins (HLPs). The first to be isolated was the Rv2633c protein, which plays a role in infection by Mycobacterium tuberculosis (Mtb), but could not be crystallized. This work presents the first crystal structure of an ortholog of Rv2633c, the mycobacterial HLP from Mycobacterium kansasii (Mka). This structure differs from those of hemerythrins and other known HLPs. It consists of five α-helices, whereas all other HLP domains have four. In contrast with other HLPs, the HLP domain is not fused to an additional protein domain. The residues ligating and surrounding the di-iron site are also unique among HLPs. Notably, a tyrosine occupies the position normally held by one of the histidine ligands in hemerythrin. This structure was used to construct a homology model of Rv2633c. The structure of five α-helices is conserved and the di-iron site ligands are identical in Rv2633c. Two residues near the ends of helices in the Mka HLP structure are replaced with prolines in the Rv2633c model. This may account for structural perturbations that decrease the solubility of Rv2633c relative to Mka HLP. Clusters of residues that differ in charge or polarity between Rv2633c and Mka HLP that point outward from the helical core could reflect a specificity for potential differential interactions with other protein partners in vivo, which are related to function. The Mka HLP exhibited weaker catalase activity than Rv2633c. Evidence was obtained for the interaction of Mka HLP irons with nitric oxide.

Dynamics of Immune Responses during Experimental Mycobacterium kansasii Infection of Cynomolgus Monkeys (Macaca fascicularis).

To profile the dynamic changes of immune responses for M. kansasii infection, 3 cynomolgus monkeys were experimentally infected with M. kansasii by intratracheal inhalation of 1 × 106 CFU bacteria per monkey. Every 2 to 4 weeks, tuberculin skin testings (TSTs) were performed and blood samples were collected for immunoassay. Multiple cytokines in a single sample were measured by Luminex xMAP technologies. IgM and IgA were detected by double-antibody sandwich ELISA. IgG against PPD and 11 M. tuberculosis proteins were detected by using of indirect ELISA. At week 16, all animals were euthanized for necropsy and histological analysis. Positivities of TSTs emerged from week 2 to 6 postinfection. Leukocyte counts and T lymphocyte subsets experienced moderate increases. Among 44 kinds of cytokines, 36 kinds of them showed increases of different dynamic types and 8 kinds of them showed no specific changes. Total IgM and IgA showed a transient increase at an early infection stage. Positivities of M. tuberculosis specific IgM and IgA emerged as early as week 2 postinfection. All animals showed positive IgG against PPD and negative IgG responses to 38 kDa, MPT64L, TB16.3, 16 kDa, U1, and MTB81 antigens during the infection period. IgG against ESAT-6, CFP10, CFP10-ESAT-6, Ag85b, and 14 kDa antigens reached positive levels. The IgG avidities of PPD, ESAT-6, CFP10-ESAT-6, and Ag85b were all above 50 percent. In conclusion, the data indicate that M. kansasii infection in monkeys can induce positivities of TSTs, increases of multiple cytokines, and cross-reactive antibody responses to M. tuberculosis antigens.

Prognosis of chronic pulmonary aspergillosis in patients with pulmonary non-tuberculous mycobacterial disease.

BACKGROUND: Pulmonary non-tuberculous mycobacterial disease (PNTM) is a known risk factor for chronic pulmonary aspergillosis (CPA). However, few studies have focused on the prognosis of PNTM-associated CPA. In the present investigation, we aimed to elucidate the clinical course and prognostic factors of CPA in patients with PNTM. METHODS: We retrospectively investigated the medical records of 62 patients with CPA and a history of PNTM who were admitted to Kinki-chuo Chest Medical Center between 2010 and 2015. Co-morbidities, causative microorganisms, radiological findings, and outcomes were evaluated. RESULTS: The patients' median age was 69.5 years, and the median follow-up period was 4.2 years. The major underlying diseases, other than PNTM and CPA, were old pulmonary tuberculosis, chronic obstructive pulmonary disease, and interstitial pneumonia. The most common causative NTM species were Mycobacterium avium complex (MAC; 37 patients; 59.7%) and Mycobacterium kansasii (20 patients; 32.3%). Survival was 83% after 1 year and 61% after 5 years. Use of systemic corticosteroids (hazard ratio: 3.32, 95% confidence interval: 1.23-9.51; P=0.00177) and C-reactive protein levels ≥ 5.0 mg/dL (hazard ratio: 8.96, 95% confidence interval: 2.15-62.9; P=0.0014) at the time of CPA diagnosis were associated with increased over-all mortality. CONCLUSIONS: CPA frequently developed in patients with MAC and M. kansasii PNTM. The treatment course of PNTM was not associated with all-cause mortality. However, systemic corticosteroid use and high CRP levels were negative prognostic factors of CPA in patients with PNTM. Since the prognosis is poor, early diagnosis and treatment of CPA are important in patients with PNTM.

Micobacterias no tuberculosas. ¿Una amenaza emergente? / Non-Tuberculous Mycobacteria. An Emerging Threat?

Introducción y objetivo: Los aislamientos de micobacterias no tuberculosas (MNT) son cada vez más frecuentes. El objetivo principal de nuestro estudio fue conocer el número y la variedad de especies de MNT en nuestra región, su distribución según el origen de la muestra, y la edad y sexo de los pacientes; asimismo, analizar pormenorizadamente los aislamientos clínicamente significativos. Metodología: Estudio prospectivo que incluye todas las MNT aisladas en Asturias durante el período 2005-2012. Las muestras se procesaron siguiendo directrices internacionalmente aceptadas. Para el tratamiento estadístico de los datos se utilizaron tablas de contingencia 2 × 2 aplicando el test exacto de Fisher. Resultados: Se aislaron 3.284 micobacterias: 1.499 Mycobacterium tuberculosis complex (MTB) y 1.785 MNT. A lo largo del estudio se incrementaron los aislamientos de MNT y se redujeron los de MTB. Los aislamientos de MNT fueron más numerosos en hombres que en mujeres (p <0,001). M. gordonae, la especie más frecuentemente aislada, no originó enfermedad en ningún caso. El aislamiento fue clínicamente significativo en 212 pacientes (17,1%), siendo M. kansasii y M. avium las especies que más frecuentemente causaron enfermedad. La diferencia de aislamientos de M. kansasii entre mujeres y hombres fue estadísticamente significativa (p < 0,01). Conclusiones: En nuestro estudio, los aislamientos de MNT se incrementaron un 35%, frente a un descenso del 21% de los casos de MTB. Tanto los aislamientos de MNT como los casos clínicamente significativos fueron más frecuentes en hombres. Solo un 17,1% de las MNT aisladas, principalmente M. avium complex (MAC) y M. kansasii, ocasionaron enfermedad

Introduction and objective: Non-tuberculous mycobacteria (NTM) isolates are becoming more common. The main objective of our study was to establish the number and diversity of NTM species in our region and their distribution according to the source sample, age and gender of the patients, and to analyse clinically significant isolates. Methodology: Prospective study of all NTM isolated in Asturias from 2005 to 2012. Samples were processed following internationally accepted guidelines. Statistical analysis was based on Fisher's exact test for 2 × 2 contingency tables. Results: A total of 3,284 mycobacteria were isolated: 1,499 Mycobacterium tuberculosis complex (MTB) and 1,785 NTM. During the study, NTM isolation rates increased while MTB isolation decreased. NTM were more frequent in men (P < .001). M. gordonae was the most frequently isolated species but did not cause disease in any case. NTM isolates from 212 patients were associated with clinically significant disease (17.1%). M. kansasii and M. avium were most commonly associated with disease. The number of M. kansasii isolates from men was statistically significant (P < .01). Conclusions: In our study, NTM isolates increased by 35%, compared with a 21% decline in cases of MTB. Both isolation of NTM and clinically significant cases were more common in men. Only 17.1% of NTM isolates were associated with disease, most commonly M. avium complex and M. kansasii

Mycobacterium kansasii Isolated from Tuberculinpositive Rhesus Macaques (Macaca mulatta) in the Absence of Disease.

Mycobacterial infections are of primary health concern in NHP colonies in biomedical research. NHP are constantly monitored and screened for Mycobacterium spp. We report 6 Chinese-origin rhesus macaques infected with Mycobacterium kansasii that exhibited positive tuberculin skin tests in the absence of disease. Two of these macaques were being used for research purposes; the remaining 4 macaques were residing at the contract quarantine company. Histopathology and acid-fast staining of fixed tissues from all macaques showed that all were free of disease. Thoracic radiographs were negative for any signs of disease or infection. Samples from bronchial lavage and tissues including lung, spleen, hilar and mesenteric lymph nodes tested negative by PCR assay for Mycobacterium spp. One of the research macaques tested culture-positive for M. kansasii and a poorly characterized M. avium complex organism. One macaque from the contract quarantine facility tested culture positive for M. kansasii. Genomic testing and target gene RNA expression analysis of the 2 M. kansasii isolates were performed to evaluate possible kinship and affected genes that might contribute to susceptibility to mycobacterial infection. Genotyping of the 2 isolates revealed 2 genetically distinct strains (strains 1 and 4). The presence of positive tuberculin skin tests in the absence of disease raises serious concerns regarding diagnostic methods used for infected NHP.

The role of hydrophobicity in tuberculosis evolution and pathogenicity.

The evolution of tubercle bacilli parallels a route from environmental Mycobacterium kansasii, through intermediate "Mycobacterium canettii", to the modern Mycobacterium tuberculosis complex. Cell envelope outer membrane lipids change systematically from hydrophilic lipooligosaccharides and phenolic glycolipids to hydrophobic phthiocerol dimycocerosates, di- and pentaacyl trehaloses and sulfoglycolipids. Such lipid changes point to a hydrophobic phenotype for M. tuberculosis sensu stricto. Using Congo Red staining and hexadecane-aqueous buffer partitioning, the hydrophobicity of rough morphology M. tuberculosis and Mycobacterium bovis strains was greater than smooth "M. canettii" and M. kansasii. Killed mycobacteria maintained differential hydrophobicity but defatted cells were similar, indicating that outer membrane lipids govern overall hydrophobicity. A rough M. tuberculosis H37Rv ΔpapA1 sulfoglycolipid-deficient mutant had significantly diminished Congo Red uptake though hexadecane-aqueous buffer partitioning was similar to H37Rv. An M. kansasii, ΔMKAN27435 partially lipooligosaccharide-deficient mutant absorbed marginally more Congo Red dye than the parent strain but was comparable in partition experiments. In evolving from ancestral mycobacteria, related to "M. canettii" and M. kansasii, modern M. tuberculosis probably became more hydrophobic by increasing the proportion of less polar lipids in the outer membrane. Importantly, such a change would enhance the capability for aerosol transmission, affecting virulence and pathogenicity.

Immune Reconstitution Inflammatory Syndrome Secondary to Mycobacterium kansasii Infection in a Kidney Transplant Recipient.

Nontuberculous mycobacteria (NTM) infection is a challenging diagnosis for clinicians in solid organ transplantation. Immune reconstitution inflammatory syndrome (IRIS) is so far unreported in this context. We report here the case of a renal transplant recipient who developed Mycobacterium kansasii-associated lymphadenitis complicated by IRIS while undergoing reduction of his immunosuppressive therapy. For IRIS, the patient required low-dose steroids and an increase in global immunosuppression, in association with NTM antibiotherapy.

Human infections due to nontuberculous mycobacteria: the infectious diseases and clinical microbiology specialists' point of view.

Nontuberculous mycobacteria (>150 species such as Mycobacterium avium, Mycobacterium kansasii, Mycobacterium chelonae and Mycobacterium abscessus) are opportunistic pathogens causing lung and extrarespiratory infections, beside M. ulcerans and M. marinum that are pathogens causing specific skin and soft tissue infections. Disseminated infections occur only in severe immunosuppressed conditions such as AIDS. The diagnosis is based on repeated isolations of the same mycobacterium associated with clinical and radiological signs, and the absence of tuberculosis. Precise species identification is obtained by molecular biology. Therapeutic antibiotic regimens differ with regard to the mycobacterial species that are involved. Prevention of iatrogenic infections relies on using sterile water in all injections, healthcare and cosmetic occupations. Future perspectives are to set effective antibiotic regimens tested in randomized therapeutic trials.

Clinical Case of the Month. A 44-Year-Old HIV-Infected Man With Righ-Shoulder Swelling.

Immunocompromised patients are susceptible to various joint infections with less-common pathogens, such as mycobacterium. Physicians should have a low threshold to investigate the cause of an arthropathy further. An aspiration of the effusion is usually warranted to identify the possible pathogen and target treatment. We report an unusual presentation of a human immunodeficiency virus-infected patient with a chronic effusion arthropathy of his right shoulder due to Mycobacterium kansasii. We review the risk factors, transmission, clinical manifestations, and management of Mycobacterium kansasii.

[Pathogenicity of Mycobacterium kansasii]. / Pathogenität von Mycobacterium kansasii.

BACKGROUND: In a recent prospective study on pulmonary infections with non-tuberculous mycobacteria (NTM) led by the WATL group, disease rates in patients with M. kansasii infection were found to be 100 %. In the present study we re-evaluated the pathogenicity of M. kansasii infections in a large lung diseases treatment center in Berlin (Lungenklinik Heckeshorn). METHODS: All patients in whose respiratory specimen cultures M. kansasii was detected between January 2003 and June 2013 were included. The 2007 ATS diagnostic criteria were applied to differentiate disease from asymptomatic infection. The strains were further investigated by sequencing of the 16S-23S rDNA internal transcribed spacer (ITS) region. RESULTS: We evaluated 43 consecutive cases. Complete patient data were available in 38 cases. In one patient, no culture results were obtained, in 37 patients M. kansasii was isolated and patient data could be retrieved. In 25/37 patients (68 %) clinical disease was present so that a specific treatment was initiated (underlying diseases were COPD in 8/25 (32 %), bronchiectasis in 5/25 (20 %), TB scar or scar due to prior chest surgery in 3/25 (12 %) and alcohol abuse in 4/25 (16 %)). Twelve out of 37 patients (32 %) were found to be colonized or asymptomatically infected (underlying diseases were COPD in 7/12 (58 %), bronchiectasis in 3/12 (25 %) and TB scar or scar due to prior chest surgery in 3/12 (25 %)). Sequencing results identified 30 strains as genotype I, and 2 strains as genotype II. In 22/30 cases (73 %) genotype I was considered pathogenic. CONCLUSIONS: In our cohort, we could not confirm the high M. kansasii pathogenicity of 100 % found in a previous multi-center study; we therefore support the clinical and semiquantitative microbiologic diagnostic criteria also for infection with M. kansasii.

Mycobacterium kansasii-induced death of murine macrophages involves endoplasmic reticulum stress responses mediated by reactive oxygen species generation or calpain activation.

Although pathogenic mechanisms of tuberculosis have been extensively studied, little is known about the pathogenic mechanisms of Mycobacterium kansasii. In this work the influence of virulence and ER-stress mediated apoptosis of macrophages during two different strains of M. kansasii infection was investigated. We show that M. kansasii infection is associated with ER stress-mediated apoptosis in the murine macrophage cell line RAW 264.7. Infection of RAW 264.7 cells in vitro with apoptosis-inducing a clinical isolate of M. kansasii SM-1 (SM-1) resulted in strong induction of ER stress responses compared with M. kansasii type strain (ATCC 12478)-infected RAW 264.7 cells. Interestingly, inhibition of calpain prevented the induction of CHOP and Bip in ATCC 12478-infected RAW 264.7 cells but not in RAW 264.7 cells infected with SM-1. In contrast, reactive oxygen species (ROS) were significantly increased only in RAW 264.7 cells infected with SM-1. We propose that ROS generation is important for triggering ER stress-mediated apoptosis during SM-1 infection, whereas ATCC 12478-induced, ER stress-mediated apoptosis is associated with calpain activation. Our results demonstrate that the ER stress pathway plays important roles in the pathogenesis of M. kansasii infections, and that different strains of M. kansasii induce different patterns of ER stress-mediated apoptosis.

Short communication: subtyping of Mycobacterium kansasii by PCR-restriction enzyme analysis of the hsp65 gene.

Mycobacterium kansasii is one of the most common causes of pulmonary disease resulting from nontuberculous mycobacteria (NTM). It is also the most frequently isolated NTM species from clinical specimens in Poland. The aim of this study was to investigate the distribution of M. kansasii subtypes among patients suspected of having pulmonary NTM disease. Fifty clinical isolates of M. kansasii recovered from as many patients with suspected mycobacterial lung disease between 2000 and 2010 in Poland were genotyped by PCR-restriction enzyme analysis (PCR-REA) of partial hsp65 gene. Mycobacterium kansasii subtype I was the only genotype to be identified among the isolates, both disease-associated and non-disease-associated. Isolation of M. kansasii subtype I from clinical specimens may be indicative of infection but may also merely represent colonization.

Induction of macrophage death by clinical strains of Mycobacterium kansasii.

Mycobacterium kansasii is a facultative intracellular pathogen causing pulmonary disease in immunocompetent patients. Little is known about the host defense against M. kansasii and its intracellular survival strategy inside macrophages. In the present study, we obtained six clinical isolates from patients with M. kansasii pulmonary disease and investigated the intracellular growth and cytotoxic effects of M. kansasii inside mouse bone marrow-derived macrophages (BMDM) as well as cytokine secretion from BMDM. Interestingly, two isolates, SM-1 and 2693-20, displayed faster growth rates and higher levels of TNF-alpha secretion from macrophages when compared to the other strains. In addition, SM-1 and 2693-20 also induced massive cell death in BMDM and THP-1 acute monocytic leukemia cells, while the slow growing strains induced significantly lower levels of cell death. This cytotoxicity was mainly caused by necrosis, not apoptosis and it was TNF-alpha-independent. Caspase inhibitors failed to block M. kansasii-induced macrophage death. In addition, necrosis caused by the fast growing strains was accompanied by the loss of mitochondrial membrane potential (DeltaPsi(m)). When dissipation of DeltaPsi(m) was inhibited by the classical mitochondrial permeability transition (MPT) inhibitor cyclosporine A (CsA), macrophage necrosis was reduced. These results suggest that clinical isolates of M. kansasii that grow faster in macrophages induce higher levels of necrosis in a DeltaPsi(m) loss-dependent manner.

Lung disease caused by nontuberculous mycobacteria.

PURPOSE OF REVIEW: Although the incidence of tuberculosis has reduced in developed countries, there is a growing interest in nontuberculous mycobacteria (NTM) as a cause of lung disease. However, NTM are a heterogeneous group and most of the data come from only three species: Mycobacterium avium complex, Mycobacterium kansasii and Mycobacterium abscessus. Still, information about these three species is confusing because it is based mainly on retrospective studies and series of clinical cases performed in developed countries. In recent years, new information has appeared about other species and the pathogenesis of NTM. RECENT FINDINGS: Epidemiological studies show that NTM infection is a worldwide phenomenon with an increasing presence in developing countries perhaps because of the implementation of tap water. Women with characteristic phenotype are at higher risk of acquiring NTM infection along with patients with defects on cystic fibrosis transmembrane conductance regulators. New studies on Mycobacterium fortuitum, Mycobacterium xenopi, Mycobacterium szulgai and Mycobacterium simiae indicate that the American Thoracic Society criteria for diagnosing NTM disease may not be useful for all species of NTM. SUMMARY: New multicentric and prospective studies are needed to clarify the pathogenesis and treatment of NTM. These organisms form a numerous and heterogeneous group and each species should be studied separately.

Region of difference 1 in nontuberculous Mycobacterium species adds a phylogenetic and taxonomical character.

The esat-6 and cfp-10 genes are essential for virulence in Mycobacterium tuberculosis. Among nontuberculous mycobacteria, we found these genes only in M. kansasii, M. szulgai, M. marinum, and M. riyadhense, with unique sequences. This adds a phylogenetic and taxonomical characteristic and may represent a virulence factor for nontuberculous mycobacteria.

Infección por Mycobacterium kansasii tras el trasplante hepático / Micobacterium kansasii infection after liver trasplantation

Las infecciones son una de las principales causas de morbilidad y mortalidad en pacientes trasplantados, dado el tratamiento con terapia inmunosupresora. Las infecciones por micobacterias no tuberculosas (MNT) son infrecuentes, pero pueden causar una gran morbilidad. El tratamiento está asociado a limitaciones terapéuticas debido al aumento de toxicidad y a las interacciones con el tratamiento inmunosupresor. Las infecciones por MNT pueden tratarse con cirugía, reduciendo la dosis de inmunosupresores y/o con antimicobacterianos. La American Thoracic Society (ATS) recomienda tratamiento con isoniazida, rifampicina y etambutol, que debe mantenerse durante 18 meses en el caso de infección pulmonar por Mycobacterium kansasii. Presentamos a continuación el caso clínico de un paciente inmunodeprimido a causa de un trasplante hepático, con evolución infausta debido a una colangitis aguda, que presentó además una infección respiratoria concomitante por un microorganismo poco frecuente, M. kansasii, en el período tardío postrasplante (AU)

Infections are one of the leading causes of morbidity and mortality in solid organ transplant recipients because of treatment with immunosuppressive agents. Infections due to nontuberculous mycobacteria (NTM) are infrequent but may be a major cause of morbidity. Treatment is associated with therapeutic limitations due to drug interactions with immunosuppressive agents and enhanced toxicity. Treatment of NTM infection most commonly involves surgery, reducing the doses of immunosuppressive medications and/or therapy with antimycobacterial medications The American Thoracic Society recommends isoniazid, rifampicin, and ethambutol. The current duration for treatment of pulmonary disease caused by Mycobacterium kansasii is 18 months. We describe the case of an immunosuppressed liver transplant recipient with poor outcome due to acute cholangitis who also developed concomitant infection with an uncommon organism, M. kansasii, in the late posttransplantation period (AU)

Detailed analysis of the radiographic presentation of Mycobacterium kansasii lung disease in patients with HIV infection.

BACKGROUND: Published criteria for the diagnosis of Mycobacterium kansasii lung disease require the presence of clinical symptoms, positive microbiologic results, and radiographic abnormalities. In patients with HIV infection, the radiographic findings of M kansasii lung disease are not well described. METHODS: Medical records and chest radiographs of all patients with HIV infection and at least one respiratory specimen culture positive for M kansasii at San Francisco General Hospital between December 1989 and July 2002 were reviewed. RESULTS: Chest radiographic results were abnormal in 75 of 83 patients (90%) included in the study. Radiographic abnormalities were diverse, with consolidation (66%) and nodules (42%) as the most frequent findings. The mid or lower lung zones were involved in 89% of patients. The pattern of radiographic abnormalities did not differ based on acid-fast bacilli smear status, the presence or absence of coexisting pulmonary infections, or CD4+ T-lymphocyte count. In multivariate Cox regression analysis, cavitation was the only radiographic abnormality independently associated with mortality (hazard ratio, 4.8; 95% confidence interval, 1.2 to 19.6). CONCLUSION: Patients with HIV infection and M kansasii lung disease present with diverse radiographic patterns, most commonly consolidation and nodules predominantly located in the mid and lower lung zones. This finding is in contrast to the upper-lobe cavitary presentation described in patients without HIV infection. Although rare, the presence of cavitary disease in patients with HIV infection and M kansasii independently predicts worse outcome. The diversity in the radiographic presentation of M kansasii lung disease implies that clinicians should obtain sputum mycobacterial culture samples from any patient with HIV infection and an abnormal chest radiograph finding.